* Re: [PATCH v6 08/15] memory-hotplug: Common APIs to support page tables hot-remove
From: Simon Jeons @ 2013-01-30 7:32 UTC (permalink / raw)
To: Tang Chen
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <5108B5D1.6050600@cn.fujitsu.com>
On Wed, 2013-01-30 at 13:55 +0800, Tang Chen wrote:
> On 01/30/2013 11:27 AM, Simon Jeons wrote:
> > On Wed, 2013-01-30 at 10:16 +0800, Tang Chen wrote:
> >> On 01/29/2013 09:04 PM, Simon Jeons wrote:
> >>> Hi Tang,
> >>> On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
> >>>> From: Wen Congyang<wency@cn.fujitsu.com>
> >>>>
> >>>> When memory is removed, the corresponding pagetables should alse be removed.
> >>>> This patch introduces some common APIs to support vmemmap pagetable and x86_64
> >>>> architecture pagetable removing.
> >>>
> >>> Why don't need to build_all_zonelists like online_pages does during
> >>> hot-add path(add_memory)?
> >>
> >> Hi Simon,
> >>
> >> As you said, build_all_zonelists is done by online_pages. When the
> >> memory device
> >> is hot-added, we cannot use it. we can only use is when we online the
> >> pages on it.
> >
> > Why?
> >
> > If a node has just one memory device and memory is small, some zone will
> > not present like zone_highmem, then hot-add another memory device and
> > zone_highmem appear, if you should build_all_zonelists this time?
>
> Hi Simon,
>
> We built zone list when the first memory on the node is hot-added.
>
> add_memory()
> |-->if (!node_online(nid)) hotadd_new_pgdat()
> |-->free_area_init_node()
> |-->build_all_zonelists()
>
> All the zones on the new node will be initialized as empty. So here, we
> build zone list.
>
> But actually we did nothing because no page is online, and zones are empty.
> In build_zonelists_node(), populated_zone(zone) will always be false.
>
> The real work of building zone list is when pages are online. :)
>
>
> And in your question, you said some small memory is there, and
> zone_normal is present.
> OK, when these pages are onlined (not added), the zone list has been
> rebuilt.
> But pages in zone_highmem is not added, which means not onlined, so we
> don't need to
> build zone list for it. And later, the zone_highmem pages are added, we
> still don't
> rebuild the zone list because the real rebuilding work is when the pages
> are onlined.
>
> I think this is the current logic. :)
Thanks for you clarify. Actually, I miss "Even if the memory is
hot-added, it is not at ready-to-use state. For using newly added
memory, you have to 'online' the memory section" in the doc. :)
>
> Thanks. :)
>
> >
> >>
> >> But we can online the pages as different types, kernel or movable (which
> >> belongs to
> >> different zones), and we can online part of the memory, not all of them.
> >> So each time we online some pages, we should check if we need to update
> >> the zone list.
> >>
> >> So I think that is why we do build_all_zonelists when online_pages.
> >> (just my opinion)
> >>
> >> Thanks. :)
> >>
> >>>
> >>>>
> >>>> All pages of virtual mapping in removed memory cannot be freedi if some pages
> >>>> used as PGD/PUD includes not only removed memory but also other memory. So the
> >>>> patch uses the following way to check whether page can be freed or not.
> >>>>
> >>>> 1. When removing memory, the page structs of the revmoved memory are filled
> >>>> with 0FD.
> >>>> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared.
> >>>> In this case, the page used as PT/PMD can be freed.
> >>>>
> >>>> Signed-off-by: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
> >>>> Signed-off-by: Jianguo Wu<wujianguo@huawei.com>
> >>>> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>
> >>>> Signed-off-by: Tang Chen<tangchen@cn.fujitsu.com>
> >>>> ---
> >>>> arch/x86/include/asm/pgtable_types.h | 1 +
> >>>> arch/x86/mm/init_64.c | 299 ++++++++++++++++++++++++++++++++++
> >>>> arch/x86/mm/pageattr.c | 47 +++---
> >>>> include/linux/bootmem.h | 1 +
> >>>> 4 files changed, 326 insertions(+), 22 deletions(-)
> >>>>
> >>>> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
> >>>> index 3c32db8..4b6fd2a 100644
> >>>> --- a/arch/x86/include/asm/pgtable_types.h
> >>>> +++ b/arch/x86/include/asm/pgtable_types.h
> >>>> @@ -352,6 +352,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
> >>>> * as a pte too.
> >>>> */
> >>>> extern pte_t *lookup_address(unsigned long address, unsigned int *level);
> >>>> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
> >>>>
> >>>> #endif /* !__ASSEMBLY__ */
> >>>>
> >>>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> >>>> index 9ac1723..fe01116 100644
> >>>> --- a/arch/x86/mm/init_64.c
> >>>> +++ b/arch/x86/mm/init_64.c
> >>>> @@ -682,6 +682,305 @@ int arch_add_memory(int nid, u64 start, u64 size)
> >>>> }
> >>>> EXPORT_SYMBOL_GPL(arch_add_memory);
> >>>>
> >>>> +#define PAGE_INUSE 0xFD
> >>>> +
> >>>> +static void __meminit free_pagetable(struct page *page, int order)
> >>>> +{
> >>>> + struct zone *zone;
> >>>> + bool bootmem = false;
> >>>> + unsigned long magic;
> >>>> + unsigned int nr_pages = 1<< order;
> >>>> +
> >>>> + /* bootmem page has reserved flag */
> >>>> + if (PageReserved(page)) {
> >>>> + __ClearPageReserved(page);
> >>>> + bootmem = true;
> >>>> +
> >>>> + magic = (unsigned long)page->lru.next;
> >>>> + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
> >>>> + while (nr_pages--)
> >>>> + put_page_bootmem(page++);
> >>>> + } else
> >>>> + __free_pages_bootmem(page, order);
> >>>> + } else
> >>>> + free_pages((unsigned long)page_address(page), order);
> >>>> +
> >>>> + /*
> >>>> + * SECTION_INFO pages and MIX_SECTION_INFO pages
> >>>> + * are all allocated by bootmem.
> >>>> + */
> >>>> + if (bootmem) {
> >>>> + zone = page_zone(page);
> >>>> + zone_span_writelock(zone);
> >>>> + zone->present_pages += nr_pages;
> >>>> + zone_span_writeunlock(zone);
> >>>> + totalram_pages += nr_pages;
> >>>> + }
> >>>> +}
> >>>> +
> >>>> +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
> >>>> +{
> >>>> + pte_t *pte;
> >>>> + int i;
> >>>> +
> >>>> + for (i = 0; i< PTRS_PER_PTE; i++) {
> >>>> + pte = pte_start + i;
> >>>> + if (pte_val(*pte))
> >>>> + return;
> >>>> + }
> >>>> +
> >>>> + /* free a pte talbe */
> >>>> + free_pagetable(pmd_page(*pmd), 0);
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pmd_clear(pmd);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> +}
> >>>> +
> >>>> +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
> >>>> +{
> >>>> + pmd_t *pmd;
> >>>> + int i;
> >>>> +
> >>>> + for (i = 0; i< PTRS_PER_PMD; i++) {
> >>>> + pmd = pmd_start + i;
> >>>> + if (pmd_val(*pmd))
> >>>> + return;
> >>>> + }
> >>>> +
> >>>> + /* free a pmd talbe */
> >>>> + free_pagetable(pud_page(*pud), 0);
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pud_clear(pud);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> +}
> >>>> +
> >>>> +/* Return true if pgd is changed, otherwise return false. */
> >>>> +static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
> >>>> +{
> >>>> + pud_t *pud;
> >>>> + int i;
> >>>> +
> >>>> + for (i = 0; i< PTRS_PER_PUD; i++) {
> >>>> + pud = pud_start + i;
> >>>> + if (pud_val(*pud))
> >>>> + return false;
> >>>> + }
> >>>> +
> >>>> + /* free a pud table */
> >>>> + free_pagetable(pgd_page(*pgd), 0);
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pgd_clear(pgd);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> +
> >>>> + return true;
> >>>> +}
> >>>> +
> >>>> +static void __meminit
> >>>> +remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
> >>>> + bool direct)
> >>>> +{
> >>>> + unsigned long next, pages = 0;
> >>>> + pte_t *pte;
> >>>> + void *page_addr;
> >>>> + phys_addr_t phys_addr;
> >>>> +
> >>>> + pte = pte_start + pte_index(addr);
> >>>> + for (; addr< end; addr = next, pte++) {
> >>>> + next = (addr + PAGE_SIZE)& PAGE_MASK;
> >>>> + if (next> end)
> >>>> + next = end;
> >>>> +
> >>>> + if (!pte_present(*pte))
> >>>> + continue;
> >>>> +
> >>>> + /*
> >>>> + * We mapped [0,1G) memory as identity mapping when
> >>>> + * initializing, in arch/x86/kernel/head_64.S. These
> >>>> + * pagetables cannot be removed.
> >>>> + */
> >>>> + phys_addr = pte_val(*pte) + (addr& PAGE_MASK);
> >>>> + if (phys_addr< (phys_addr_t)0x40000000)
> >>>> + return;
> >>>> +
> >>>> + if (IS_ALIGNED(addr, PAGE_SIZE)&&
> >>>> + IS_ALIGNED(next, PAGE_SIZE)) {
> >>>> + if (!direct) {
> >>>> + free_pagetable(pte_page(*pte), 0);
> >>>> + pages++;
> >>>> + }
> >>>> +
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pte_clear(&init_mm, addr, pte);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> + } else {
> >>>> + /*
> >>>> + * If we are not removing the whole page, it means
> >>>> + * other ptes in this page are being used and we canot
> >>>> + * remove them. So fill the unused ptes with 0xFD, and
> >>>> + * remove the page when it is wholly filled with 0xFD.
> >>>> + */
> >>>> + memset((void *)addr, PAGE_INUSE, next - addr);
> >>>> + page_addr = page_address(pte_page(*pte));
> >>>> +
> >>>> + if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
> >>>> + free_pagetable(pte_page(*pte), 0);
> >>>> + pages++;
> >>>> +
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pte_clear(&init_mm, addr, pte);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> + }
> >>>> + }
> >>>> + }
> >>>> +
> >>>> + /* Call free_pte_table() in remove_pmd_table(). */
> >>>> + flush_tlb_all();
> >>>> + if (direct)
> >>>> + update_page_count(PG_LEVEL_4K, -pages);
> >>>> +}
> >>>> +
> >>>> +static void __meminit
> >>>> +remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
> >>>> + bool direct)
> >>>> +{
> >>>> + unsigned long pte_phys, next, pages = 0;
> >>>> + pte_t *pte_base;
> >>>> + pmd_t *pmd;
> >>>> +
> >>>> + pmd = pmd_start + pmd_index(addr);
> >>>> + for (; addr< end; addr = next, pmd++) {
> >>>> + next = pmd_addr_end(addr, end);
> >>>> +
> >>>> + if (!pmd_present(*pmd))
> >>>> + continue;
> >>>> +
> >>>> + if (pmd_large(*pmd)) {
> >>>> + if (IS_ALIGNED(addr, PMD_SIZE)&&
> >>>> + IS_ALIGNED(next, PMD_SIZE)) {
> >>>> + if (!direct) {
> >>>> + free_pagetable(pmd_page(*pmd),
> >>>> + get_order(PMD_SIZE));
> >>>> + pages++;
> >>>> + }
> >>>> +
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pmd_clear(pmd);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> + continue;
> >>>> + }
> >>>> +
> >>>> + /*
> >>>> + * We use 2M page, but we need to remove part of them,
> >>>> + * so split 2M page to 4K page.
> >>>> + */
> >>>> + pte_base = (pte_t *)alloc_low_page(&pte_phys);
> >>>> + BUG_ON(!pte_base);
> >>>> + __split_large_page((pte_t *)pmd, addr,
> >>>> + (pte_t *)pte_base);
> >>>> +
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> +
> >>>> + flush_tlb_all();
> >>>> + }
> >>>> +
> >>>> + pte_base = (pte_t *)map_low_page((pte_t *)pmd_page_vaddr(*pmd));
> >>>> + remove_pte_table(pte_base, addr, next, direct);
> >>>> + free_pte_table(pte_base, pmd);
> >>>> + unmap_low_page(pte_base);
> >>>> + }
> >>>> +
> >>>> + /* Call free_pmd_table() in remove_pud_table(). */
> >>>> + if (direct)
> >>>> + update_page_count(PG_LEVEL_2M, -pages);
> >>>> +}
> >>>> +
> >>>> +static void __meminit
> >>>> +remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
> >>>> + bool direct)
> >>>> +{
> >>>> + unsigned long pmd_phys, next, pages = 0;
> >>>> + pmd_t *pmd_base;
> >>>> + pud_t *pud;
> >>>> +
> >>>> + pud = pud_start + pud_index(addr);
> >>>> + for (; addr< end; addr = next, pud++) {
> >>>> + next = pud_addr_end(addr, end);
> >>>> +
> >>>> + if (!pud_present(*pud))
> >>>> + continue;
> >>>> +
> >>>> + if (pud_large(*pud)) {
> >>>> + if (IS_ALIGNED(addr, PUD_SIZE)&&
> >>>> + IS_ALIGNED(next, PUD_SIZE)) {
> >>>> + if (!direct) {
> >>>> + free_pagetable(pud_page(*pud),
> >>>> + get_order(PUD_SIZE));
> >>>> + pages++;
> >>>> + }
> >>>> +
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pud_clear(pud);
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> + continue;
> >>>> + }
> >>>> +
> >>>> + /*
> >>>> + * We use 1G page, but we need to remove part of them,
> >>>> + * so split 1G page to 2M page.
> >>>> + */
> >>>> + pmd_base = (pmd_t *)alloc_low_page(&pmd_phys);
> >>>> + BUG_ON(!pmd_base);
> >>>> + __split_large_page((pte_t *)pud, addr,
> >>>> + (pte_t *)pmd_base);
> >>>> +
> >>>> + spin_lock(&init_mm.page_table_lock);
> >>>> + pud_populate(&init_mm, pud, __va(pmd_phys));
> >>>> + spin_unlock(&init_mm.page_table_lock);
> >>>> +
> >>>> + flush_tlb_all();
> >>>> + }
> >>>> +
> >>>> + pmd_base = (pmd_t *)map_low_page((pmd_t *)pud_page_vaddr(*pud));
> >>>> + remove_pmd_table(pmd_base, addr, next, direct);
> >>>> + free_pmd_table(pmd_base, pud);
> >>>> + unmap_low_page(pmd_base);
> >>>> + }
> >>>> +
> >>>> + if (direct)
> >>>> + update_page_count(PG_LEVEL_1G, -pages);
> >>>> +}
> >>>> +
> >>>> +/* start and end are both virtual address. */
> >>>> +static void __meminit
> >>>> +remove_pagetable(unsigned long start, unsigned long end, bool direct)
> >>>> +{
> >>>> + unsigned long next;
> >>>> + pgd_t *pgd;
> >>>> + pud_t *pud;
> >>>> + bool pgd_changed = false;
> >>>> +
> >>>> + for (; start< end; start = next) {
> >>>> + pgd = pgd_offset_k(start);
> >>>> + if (!pgd_present(*pgd))
> >>>> + continue;
> >>>> +
> >>>> + next = pgd_addr_end(start, end);
> >>>> +
> >>>> + pud = (pud_t *)map_low_page((pud_t *)pgd_page_vaddr(*pgd));
> >>>> + remove_pud_table(pud, start, next, direct);
> >>>> + if (free_pud_table(pud, pgd))
> >>>> + pgd_changed = true;
> >>>> + unmap_low_page(pud);
> >>>> + }
> >>>> +
> >>>> + if (pgd_changed)
> >>>> + sync_global_pgds(start, end - 1);
> >>>> +
> >>>> + flush_tlb_all();
> >>>> +}
> >>>> +
> >>>> #ifdef CONFIG_MEMORY_HOTREMOVE
> >>>> int __ref arch_remove_memory(u64 start, u64 size)
> >>>> {
> >>>> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
> >>>> index a718e0d..7dcb6f9 100644
> >>>> --- a/arch/x86/mm/pageattr.c
> >>>> +++ b/arch/x86/mm/pageattr.c
> >>>> @@ -501,21 +501,13 @@ out_unlock:
> >>>> return do_split;
> >>>> }
> >>>>
> >>>> -static int split_large_page(pte_t *kpte, unsigned long address)
> >>>> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
> >>>> {
> >>>> unsigned long pfn, pfninc = 1;
> >>>> unsigned int i, level;
> >>>> - pte_t *pbase, *tmp;
> >>>> + pte_t *tmp;
> >>>> pgprot_t ref_prot;
> >>>> - struct page *base;
> >>>> -
> >>>> - if (!debug_pagealloc)
> >>>> - spin_unlock(&cpa_lock);
> >>>> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
> >>>> - if (!debug_pagealloc)
> >>>> - spin_lock(&cpa_lock);
> >>>> - if (!base)
> >>>> - return -ENOMEM;
> >>>> + struct page *base = virt_to_page(pbase);
> >>>>
> >>>> spin_lock(&pgd_lock);
> >>>> /*
> >>>> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
> >>>> * up for us already:
> >>>> */
> >>>> tmp = lookup_address(address,&level);
> >>>> - if (tmp != kpte)
> >>>> - goto out_unlock;
> >>>> + if (tmp != kpte) {
> >>>> + spin_unlock(&pgd_lock);
> >>>> + return 1;
> >>>> + }
> >>>>
> >>>> - pbase = (pte_t *)page_address(base);
> >>>> paravirt_alloc_pte(&init_mm, page_to_pfn(base));
> >>>> ref_prot = pte_pgprot(pte_clrhuge(*kpte));
> >>>> /*
> >>>> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
> >>>> * going on.
> >>>> */
> >>>> __flush_tlb_all();
> >>>> + spin_unlock(&pgd_lock);
> >>>>
> >>>> - base = NULL;
> >>>> + return 0;
> >>>> +}
> >>>>
> >>>> -out_unlock:
> >>>> - /*
> >>>> - * If we dropped out via the lookup_address check under
> >>>> - * pgd_lock then stick the page back into the pool:
> >>>> - */
> >>>> - if (base)
> >>>> +static int split_large_page(pte_t *kpte, unsigned long address)
> >>>> +{
> >>>> + pte_t *pbase;
> >>>> + struct page *base;
> >>>> +
> >>>> + if (!debug_pagealloc)
> >>>> + spin_unlock(&cpa_lock);
> >>>> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
> >>>> + if (!debug_pagealloc)
> >>>> + spin_lock(&cpa_lock);
> >>>> + if (!base)
> >>>> + return -ENOMEM;
> >>>> +
> >>>> + pbase = (pte_t *)page_address(base);
> >>>> + if (__split_large_page(kpte, address, pbase))
> >>>> __free_page(base);
> >>>> - spin_unlock(&pgd_lock);
> >>>>
> >>>> return 0;
> >>>> }
> >>>> diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
> >>>> index 3f778c2..190ff06 100644
> >>>> --- a/include/linux/bootmem.h
> >>>> +++ b/include/linux/bootmem.h
> >>>> @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
> >>>> unsigned long size);
> >>>> extern void free_bootmem(unsigned long physaddr, unsigned long size);
> >>>> extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
> >>>> +extern void __free_pages_bootmem(struct page *page, unsigned int order);
> >>>>
> >>>> /*
> >>>> * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
> >>>
> >>>
> >>> --
> >>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> >>> the body of a message to majordomo@vger.kernel.org
> >>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> >>>
> >>
> >> --
> >> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> >> the body to majordomo@kvack.org. For more info on Linux MM,
> >> see: http://www.linux-mm.org/ .
> >> Don't email:<a href=mailto:"dont@kvack.org"> email@kvack.org</a>
> >
> >
> >
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply
* Re: [PATCH] powerpc/mm: Fix hash computation function
From: Mike Qiu @ 2013-01-30 7:23 UTC (permalink / raw)
To: linuxppc-dev; +Cc: paulus, Aneesh Kumar K.V
In-Reply-To: <1359524442-5861-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
With the fix, the machine can boot up successfully
Tested-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
于 2013/1/30 13:40, Aneesh Kumar K.V 写道:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> The ASM version of hash computation function was truncating the upper bit.
> Make the ASM version similar to hpt_hash function. Remove masking vsid bits.
> Without this patch, we observed hang during bootup due to not satisfying page
> fault request correctly. The fault handler used wrong hash values to update
> the HPTE. Hence we kept looping with page fault.
>
> hash_page(ea=000001003e260008, access=203, trap=300 ip=3fff91787134 dsisr 42000000
> The computed value of hash 000000000f22f390
> update: avpnv=4003e46054003e00, hash=000000000722f390, f=80000006, psize: 2 ...
>
> Reported-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> arch/powerpc/mm/hash_low_64.S | 62 +++++++++++++++++++++++------------------
> 1 file changed, 35 insertions(+), 27 deletions(-)
>
> diff --git a/arch/powerpc/mm/hash_low_64.S b/arch/powerpc/mm/hash_low_64.S
> index 5658508..7443481 100644
> --- a/arch/powerpc/mm/hash_low_64.S
> +++ b/arch/powerpc/mm/hash_low_64.S
> @@ -115,11 +115,13 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
> sldi r29,r5,SID_SHIFT - VPN_SHIFT
> rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
> or r29,r28,r29
> -
> - /* Calculate hash value for primary slot and store it in r28 */
> - rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
> - rldicl r0,r3,64-12,48 /* (ea >> 12) & 0xffff */
> - xor r28,r5,r0
> + /*
> + * Calculate hash value for primary slot and store it in r28
> + * r3 = va, r5 = vsid
> + * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
> + */
> + rldicl r0,r3,64-12,48
> + xor r28,r5,r0 /* hash */
> b 4f
>
> 3: /* Calc vpn and put it in r29 */
> @@ -130,11 +132,12 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
> /*
> * calculate hash value for primary slot and
> * store it in r28 for 1T segment
> + * r3 = va, r5 = vsid
> */
> - rldic r28,r5,25,25 /* (vsid << 25) & 0x7fffffffff */
> - clrldi r5,r5,40 /* vsid & 0xffffff */
> - rldicl r0,r3,64-12,36 /* (ea >> 12) & 0xfffffff */
> - xor r28,r28,r5
> + sldi r28,r5,25 /* vsid << 25 */
> + /* r0 = (va >> 12) & ((1ul << (40 - 12)) -1) */
> + rldicl r0,r3,64-12,36
> + xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
> xor r28,r28,r0 /* hash */
>
> /* Convert linux PTE bits into HW equivalents */
> @@ -407,11 +410,13 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
> */
> rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
> or r29,r28,r29
> -
> - /* Calculate hash value for primary slot and store it in r28 */
> - rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
> - rldicl r0,r3,64-12,48 /* (ea >> 12) & 0xffff */
> - xor r28,r5,r0
> + /*
> + * Calculate hash value for primary slot and store it in r28
> + * r3 = va, r5 = vsid
> + * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
> + */
> + rldicl r0,r3,64-12,48
> + xor r28,r5,r0 /* hash */
> b 4f
>
> 3: /* Calc vpn and put it in r29 */
> @@ -426,11 +431,12 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
> /*
> * Calculate hash value for primary slot and
> * store it in r28 for 1T segment
> + * r3 = va, r5 = vsid
> */
> - rldic r28,r5,25,25 /* (vsid << 25) & 0x7fffffffff */
> - clrldi r5,r5,40 /* vsid & 0xffffff */
> - rldicl r0,r3,64-12,36 /* (ea >> 12) & 0xfffffff */
> - xor r28,r28,r5
> + sldi r28,r5,25 /* vsid << 25 */
> + /* r0 = (va >> 12) & ((1ul << (40 - 12)) -1) */
> + rldicl r0,r3,64-12,36
> + xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
> xor r28,r28,r0 /* hash */
>
> /* Convert linux PTE bits into HW equivalents */
> @@ -752,25 +758,27 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
> rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
> or r29,r28,r29
>
> - /* Calculate hash value for primary slot and store it in r28 */
> - rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
> - rldicl r0,r3,64-16,52 /* (ea >> 16) & 0xfff */
> - xor r28,r5,r0
> + /* Calculate hash value for primary slot and store it in r28
> + * r3 = va, r5 = vsid
> + * r0 = (va >> 16) & ((1ul << (28 - 16)) -1)
> + */
> + rldicl r0,r3,64-16,52
> + xor r28,r5,r0 /* hash */
> b 4f
>
> 3: /* Calc vpn and put it in r29 */
> sldi r29,r5,SID_SHIFT_1T - VPN_SHIFT
> rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT_1T - VPN_SHIFT)
> or r29,r28,r29
> -
> /*
> * calculate hash value for primary slot and
> * store it in r28 for 1T segment
> + * r3 = va, r5 = vsid
> */
> - rldic r28,r5,25,25 /* (vsid << 25) & 0x7fffffffff */
> - clrldi r5,r5,40 /* vsid & 0xffffff */
> - rldicl r0,r3,64-16,40 /* (ea >> 16) & 0xffffff */
> - xor r28,r28,r5
> + sldi r28,r5,25 /* vsid << 25 */
> + /* r0 = (va >> 16) & ((1ul << (40 - 16)) -1) */
> + rldicl r0,r3,64-16,40
> + xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
> xor r28,r28,r0 /* hash */
>
> /* Convert linux PTE bits into HW equivalents */
^ permalink raw reply
* Re: [PATCH v6 08/15] memory-hotplug: Common APIs to support page tables hot-remove
From: Tang Chen @ 2013-01-30 5:55 UTC (permalink / raw)
To: Simon Jeons
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <1359516425.1288.5.camel@kernel>
On 01/30/2013 11:27 AM, Simon Jeons wrote:
> On Wed, 2013-01-30 at 10:16 +0800, Tang Chen wrote:
>> On 01/29/2013 09:04 PM, Simon Jeons wrote:
>>> Hi Tang,
>>> On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
>>>> From: Wen Congyang<wency@cn.fujitsu.com>
>>>>
>>>> When memory is removed, the corresponding pagetables should alse be removed.
>>>> This patch introduces some common APIs to support vmemmap pagetable and x86_64
>>>> architecture pagetable removing.
>>>
>>> Why don't need to build_all_zonelists like online_pages does during
>>> hot-add path(add_memory)?
>>
>> Hi Simon,
>>
>> As you said, build_all_zonelists is done by online_pages. When the
>> memory device
>> is hot-added, we cannot use it. we can only use is when we online the
>> pages on it.
>
> Why?
>
> If a node has just one memory device and memory is small, some zone will
> not present like zone_highmem, then hot-add another memory device and
> zone_highmem appear, if you should build_all_zonelists this time?
Hi Simon,
We built zone list when the first memory on the node is hot-added.
add_memory()
|-->if (!node_online(nid)) hotadd_new_pgdat()
|-->free_area_init_node()
|-->build_all_zonelists()
All the zones on the new node will be initialized as empty. So here, we
build zone list.
But actually we did nothing because no page is online, and zones are empty.
In build_zonelists_node(), populated_zone(zone) will always be false.
The real work of building zone list is when pages are online. :)
And in your question, you said some small memory is there, and
zone_normal is present.
OK, when these pages are onlined (not added), the zone list has been
rebuilt.
But pages in zone_highmem is not added, which means not onlined, so we
don't need to
build zone list for it. And later, the zone_highmem pages are added, we
still don't
rebuild the zone list because the real rebuilding work is when the pages
are onlined.
I think this is the current logic. :)
Thanks. :)
>
>>
>> But we can online the pages as different types, kernel or movable (which
>> belongs to
>> different zones), and we can online part of the memory, not all of them.
>> So each time we online some pages, we should check if we need to update
>> the zone list.
>>
>> So I think that is why we do build_all_zonelists when online_pages.
>> (just my opinion)
>>
>> Thanks. :)
>>
>>>
>>>>
>>>> All pages of virtual mapping in removed memory cannot be freedi if some pages
>>>> used as PGD/PUD includes not only removed memory but also other memory. So the
>>>> patch uses the following way to check whether page can be freed or not.
>>>>
>>>> 1. When removing memory, the page structs of the revmoved memory are filled
>>>> with 0FD.
>>>> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared.
>>>> In this case, the page used as PT/PMD can be freed.
>>>>
>>>> Signed-off-by: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
>>>> Signed-off-by: Jianguo Wu<wujianguo@huawei.com>
>>>> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>
>>>> Signed-off-by: Tang Chen<tangchen@cn.fujitsu.com>
>>>> ---
>>>> arch/x86/include/asm/pgtable_types.h | 1 +
>>>> arch/x86/mm/init_64.c | 299 ++++++++++++++++++++++++++++++++++
>>>> arch/x86/mm/pageattr.c | 47 +++---
>>>> include/linux/bootmem.h | 1 +
>>>> 4 files changed, 326 insertions(+), 22 deletions(-)
>>>>
>>>> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
>>>> index 3c32db8..4b6fd2a 100644
>>>> --- a/arch/x86/include/asm/pgtable_types.h
>>>> +++ b/arch/x86/include/asm/pgtable_types.h
>>>> @@ -352,6 +352,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
>>>> * as a pte too.
>>>> */
>>>> extern pte_t *lookup_address(unsigned long address, unsigned int *level);
>>>> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
>>>>
>>>> #endif /* !__ASSEMBLY__ */
>>>>
>>>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
>>>> index 9ac1723..fe01116 100644
>>>> --- a/arch/x86/mm/init_64.c
>>>> +++ b/arch/x86/mm/init_64.c
>>>> @@ -682,6 +682,305 @@ int arch_add_memory(int nid, u64 start, u64 size)
>>>> }
>>>> EXPORT_SYMBOL_GPL(arch_add_memory);
>>>>
>>>> +#define PAGE_INUSE 0xFD
>>>> +
>>>> +static void __meminit free_pagetable(struct page *page, int order)
>>>> +{
>>>> + struct zone *zone;
>>>> + bool bootmem = false;
>>>> + unsigned long magic;
>>>> + unsigned int nr_pages = 1<< order;
>>>> +
>>>> + /* bootmem page has reserved flag */
>>>> + if (PageReserved(page)) {
>>>> + __ClearPageReserved(page);
>>>> + bootmem = true;
>>>> +
>>>> + magic = (unsigned long)page->lru.next;
>>>> + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
>>>> + while (nr_pages--)
>>>> + put_page_bootmem(page++);
>>>> + } else
>>>> + __free_pages_bootmem(page, order);
>>>> + } else
>>>> + free_pages((unsigned long)page_address(page), order);
>>>> +
>>>> + /*
>>>> + * SECTION_INFO pages and MIX_SECTION_INFO pages
>>>> + * are all allocated by bootmem.
>>>> + */
>>>> + if (bootmem) {
>>>> + zone = page_zone(page);
>>>> + zone_span_writelock(zone);
>>>> + zone->present_pages += nr_pages;
>>>> + zone_span_writeunlock(zone);
>>>> + totalram_pages += nr_pages;
>>>> + }
>>>> +}
>>>> +
>>>> +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
>>>> +{
>>>> + pte_t *pte;
>>>> + int i;
>>>> +
>>>> + for (i = 0; i< PTRS_PER_PTE; i++) {
>>>> + pte = pte_start + i;
>>>> + if (pte_val(*pte))
>>>> + return;
>>>> + }
>>>> +
>>>> + /* free a pte talbe */
>>>> + free_pagetable(pmd_page(*pmd), 0);
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pmd_clear(pmd);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> +}
>>>> +
>>>> +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
>>>> +{
>>>> + pmd_t *pmd;
>>>> + int i;
>>>> +
>>>> + for (i = 0; i< PTRS_PER_PMD; i++) {
>>>> + pmd = pmd_start + i;
>>>> + if (pmd_val(*pmd))
>>>> + return;
>>>> + }
>>>> +
>>>> + /* free a pmd talbe */
>>>> + free_pagetable(pud_page(*pud), 0);
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pud_clear(pud);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> +}
>>>> +
>>>> +/* Return true if pgd is changed, otherwise return false. */
>>>> +static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
>>>> +{
>>>> + pud_t *pud;
>>>> + int i;
>>>> +
>>>> + for (i = 0; i< PTRS_PER_PUD; i++) {
>>>> + pud = pud_start + i;
>>>> + if (pud_val(*pud))
>>>> + return false;
>>>> + }
>>>> +
>>>> + /* free a pud table */
>>>> + free_pagetable(pgd_page(*pgd), 0);
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pgd_clear(pgd);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> +
>>>> + return true;
>>>> +}
>>>> +
>>>> +static void __meminit
>>>> +remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
>>>> + bool direct)
>>>> +{
>>>> + unsigned long next, pages = 0;
>>>> + pte_t *pte;
>>>> + void *page_addr;
>>>> + phys_addr_t phys_addr;
>>>> +
>>>> + pte = pte_start + pte_index(addr);
>>>> + for (; addr< end; addr = next, pte++) {
>>>> + next = (addr + PAGE_SIZE)& PAGE_MASK;
>>>> + if (next> end)
>>>> + next = end;
>>>> +
>>>> + if (!pte_present(*pte))
>>>> + continue;
>>>> +
>>>> + /*
>>>> + * We mapped [0,1G) memory as identity mapping when
>>>> + * initializing, in arch/x86/kernel/head_64.S. These
>>>> + * pagetables cannot be removed.
>>>> + */
>>>> + phys_addr = pte_val(*pte) + (addr& PAGE_MASK);
>>>> + if (phys_addr< (phys_addr_t)0x40000000)
>>>> + return;
>>>> +
>>>> + if (IS_ALIGNED(addr, PAGE_SIZE)&&
>>>> + IS_ALIGNED(next, PAGE_SIZE)) {
>>>> + if (!direct) {
>>>> + free_pagetable(pte_page(*pte), 0);
>>>> + pages++;
>>>> + }
>>>> +
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pte_clear(&init_mm, addr, pte);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> + } else {
>>>> + /*
>>>> + * If we are not removing the whole page, it means
>>>> + * other ptes in this page are being used and we canot
>>>> + * remove them. So fill the unused ptes with 0xFD, and
>>>> + * remove the page when it is wholly filled with 0xFD.
>>>> + */
>>>> + memset((void *)addr, PAGE_INUSE, next - addr);
>>>> + page_addr = page_address(pte_page(*pte));
>>>> +
>>>> + if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
>>>> + free_pagetable(pte_page(*pte), 0);
>>>> + pages++;
>>>> +
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pte_clear(&init_mm, addr, pte);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> + }
>>>> + }
>>>> + }
>>>> +
>>>> + /* Call free_pte_table() in remove_pmd_table(). */
>>>> + flush_tlb_all();
>>>> + if (direct)
>>>> + update_page_count(PG_LEVEL_4K, -pages);
>>>> +}
>>>> +
>>>> +static void __meminit
>>>> +remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
>>>> + bool direct)
>>>> +{
>>>> + unsigned long pte_phys, next, pages = 0;
>>>> + pte_t *pte_base;
>>>> + pmd_t *pmd;
>>>> +
>>>> + pmd = pmd_start + pmd_index(addr);
>>>> + for (; addr< end; addr = next, pmd++) {
>>>> + next = pmd_addr_end(addr, end);
>>>> +
>>>> + if (!pmd_present(*pmd))
>>>> + continue;
>>>> +
>>>> + if (pmd_large(*pmd)) {
>>>> + if (IS_ALIGNED(addr, PMD_SIZE)&&
>>>> + IS_ALIGNED(next, PMD_SIZE)) {
>>>> + if (!direct) {
>>>> + free_pagetable(pmd_page(*pmd),
>>>> + get_order(PMD_SIZE));
>>>> + pages++;
>>>> + }
>>>> +
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pmd_clear(pmd);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> + continue;
>>>> + }
>>>> +
>>>> + /*
>>>> + * We use 2M page, but we need to remove part of them,
>>>> + * so split 2M page to 4K page.
>>>> + */
>>>> + pte_base = (pte_t *)alloc_low_page(&pte_phys);
>>>> + BUG_ON(!pte_base);
>>>> + __split_large_page((pte_t *)pmd, addr,
>>>> + (pte_t *)pte_base);
>>>> +
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> +
>>>> + flush_tlb_all();
>>>> + }
>>>> +
>>>> + pte_base = (pte_t *)map_low_page((pte_t *)pmd_page_vaddr(*pmd));
>>>> + remove_pte_table(pte_base, addr, next, direct);
>>>> + free_pte_table(pte_base, pmd);
>>>> + unmap_low_page(pte_base);
>>>> + }
>>>> +
>>>> + /* Call free_pmd_table() in remove_pud_table(). */
>>>> + if (direct)
>>>> + update_page_count(PG_LEVEL_2M, -pages);
>>>> +}
>>>> +
>>>> +static void __meminit
>>>> +remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
>>>> + bool direct)
>>>> +{
>>>> + unsigned long pmd_phys, next, pages = 0;
>>>> + pmd_t *pmd_base;
>>>> + pud_t *pud;
>>>> +
>>>> + pud = pud_start + pud_index(addr);
>>>> + for (; addr< end; addr = next, pud++) {
>>>> + next = pud_addr_end(addr, end);
>>>> +
>>>> + if (!pud_present(*pud))
>>>> + continue;
>>>> +
>>>> + if (pud_large(*pud)) {
>>>> + if (IS_ALIGNED(addr, PUD_SIZE)&&
>>>> + IS_ALIGNED(next, PUD_SIZE)) {
>>>> + if (!direct) {
>>>> + free_pagetable(pud_page(*pud),
>>>> + get_order(PUD_SIZE));
>>>> + pages++;
>>>> + }
>>>> +
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pud_clear(pud);
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> + continue;
>>>> + }
>>>> +
>>>> + /*
>>>> + * We use 1G page, but we need to remove part of them,
>>>> + * so split 1G page to 2M page.
>>>> + */
>>>> + pmd_base = (pmd_t *)alloc_low_page(&pmd_phys);
>>>> + BUG_ON(!pmd_base);
>>>> + __split_large_page((pte_t *)pud, addr,
>>>> + (pte_t *)pmd_base);
>>>> +
>>>> + spin_lock(&init_mm.page_table_lock);
>>>> + pud_populate(&init_mm, pud, __va(pmd_phys));
>>>> + spin_unlock(&init_mm.page_table_lock);
>>>> +
>>>> + flush_tlb_all();
>>>> + }
>>>> +
>>>> + pmd_base = (pmd_t *)map_low_page((pmd_t *)pud_page_vaddr(*pud));
>>>> + remove_pmd_table(pmd_base, addr, next, direct);
>>>> + free_pmd_table(pmd_base, pud);
>>>> + unmap_low_page(pmd_base);
>>>> + }
>>>> +
>>>> + if (direct)
>>>> + update_page_count(PG_LEVEL_1G, -pages);
>>>> +}
>>>> +
>>>> +/* start and end are both virtual address. */
>>>> +static void __meminit
>>>> +remove_pagetable(unsigned long start, unsigned long end, bool direct)
>>>> +{
>>>> + unsigned long next;
>>>> + pgd_t *pgd;
>>>> + pud_t *pud;
>>>> + bool pgd_changed = false;
>>>> +
>>>> + for (; start< end; start = next) {
>>>> + pgd = pgd_offset_k(start);
>>>> + if (!pgd_present(*pgd))
>>>> + continue;
>>>> +
>>>> + next = pgd_addr_end(start, end);
>>>> +
>>>> + pud = (pud_t *)map_low_page((pud_t *)pgd_page_vaddr(*pgd));
>>>> + remove_pud_table(pud, start, next, direct);
>>>> + if (free_pud_table(pud, pgd))
>>>> + pgd_changed = true;
>>>> + unmap_low_page(pud);
>>>> + }
>>>> +
>>>> + if (pgd_changed)
>>>> + sync_global_pgds(start, end - 1);
>>>> +
>>>> + flush_tlb_all();
>>>> +}
>>>> +
>>>> #ifdef CONFIG_MEMORY_HOTREMOVE
>>>> int __ref arch_remove_memory(u64 start, u64 size)
>>>> {
>>>> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
>>>> index a718e0d..7dcb6f9 100644
>>>> --- a/arch/x86/mm/pageattr.c
>>>> +++ b/arch/x86/mm/pageattr.c
>>>> @@ -501,21 +501,13 @@ out_unlock:
>>>> return do_split;
>>>> }
>>>>
>>>> -static int split_large_page(pte_t *kpte, unsigned long address)
>>>> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
>>>> {
>>>> unsigned long pfn, pfninc = 1;
>>>> unsigned int i, level;
>>>> - pte_t *pbase, *tmp;
>>>> + pte_t *tmp;
>>>> pgprot_t ref_prot;
>>>> - struct page *base;
>>>> -
>>>> - if (!debug_pagealloc)
>>>> - spin_unlock(&cpa_lock);
>>>> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
>>>> - if (!debug_pagealloc)
>>>> - spin_lock(&cpa_lock);
>>>> - if (!base)
>>>> - return -ENOMEM;
>>>> + struct page *base = virt_to_page(pbase);
>>>>
>>>> spin_lock(&pgd_lock);
>>>> /*
>>>> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
>>>> * up for us already:
>>>> */
>>>> tmp = lookup_address(address,&level);
>>>> - if (tmp != kpte)
>>>> - goto out_unlock;
>>>> + if (tmp != kpte) {
>>>> + spin_unlock(&pgd_lock);
>>>> + return 1;
>>>> + }
>>>>
>>>> - pbase = (pte_t *)page_address(base);
>>>> paravirt_alloc_pte(&init_mm, page_to_pfn(base));
>>>> ref_prot = pte_pgprot(pte_clrhuge(*kpte));
>>>> /*
>>>> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
>>>> * going on.
>>>> */
>>>> __flush_tlb_all();
>>>> + spin_unlock(&pgd_lock);
>>>>
>>>> - base = NULL;
>>>> + return 0;
>>>> +}
>>>>
>>>> -out_unlock:
>>>> - /*
>>>> - * If we dropped out via the lookup_address check under
>>>> - * pgd_lock then stick the page back into the pool:
>>>> - */
>>>> - if (base)
>>>> +static int split_large_page(pte_t *kpte, unsigned long address)
>>>> +{
>>>> + pte_t *pbase;
>>>> + struct page *base;
>>>> +
>>>> + if (!debug_pagealloc)
>>>> + spin_unlock(&cpa_lock);
>>>> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
>>>> + if (!debug_pagealloc)
>>>> + spin_lock(&cpa_lock);
>>>> + if (!base)
>>>> + return -ENOMEM;
>>>> +
>>>> + pbase = (pte_t *)page_address(base);
>>>> + if (__split_large_page(kpte, address, pbase))
>>>> __free_page(base);
>>>> - spin_unlock(&pgd_lock);
>>>>
>>>> return 0;
>>>> }
>>>> diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
>>>> index 3f778c2..190ff06 100644
>>>> --- a/include/linux/bootmem.h
>>>> +++ b/include/linux/bootmem.h
>>>> @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
>>>> unsigned long size);
>>>> extern void free_bootmem(unsigned long physaddr, unsigned long size);
>>>> extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
>>>> +extern void __free_pages_bootmem(struct page *page, unsigned int order);
>>>>
>>>> /*
>>>> * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
>>>
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>
>> --
>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>> the body to majordomo@kvack.org. For more info on Linux MM,
>> see: http://www.linux-mm.org/ .
>> Don't email:<a href=mailto:"dont@kvack.org"> email@kvack.org</a>
>
>
>
^ permalink raw reply
* [PATCH] powerpc/mm: Fix hash computation function
From: Aneesh Kumar K.V @ 2013-01-30 5:40 UTC (permalink / raw)
To: benh, paulus; +Cc: Mike Qiu, linuxppc-dev, Aneesh Kumar K.V
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
The ASM version of hash computation function was truncating the upper bit.
Make the ASM version similar to hpt_hash function. Remove masking vsid bits.
Without this patch, we observed hang during bootup due to not satisfying page
fault request correctly. The fault handler used wrong hash values to update
the HPTE. Hence we kept looping with page fault.
hash_page(ea=000001003e260008, access=203, trap=300 ip=3fff91787134 dsisr 42000000
The computed value of hash 000000000f22f390
update: avpnv=4003e46054003e00, hash=000000000722f390, f=80000006, psize: 2 ...
Reported-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/mm/hash_low_64.S | 62 +++++++++++++++++++++++------------------
1 file changed, 35 insertions(+), 27 deletions(-)
diff --git a/arch/powerpc/mm/hash_low_64.S b/arch/powerpc/mm/hash_low_64.S
index 5658508..7443481 100644
--- a/arch/powerpc/mm/hash_low_64.S
+++ b/arch/powerpc/mm/hash_low_64.S
@@ -115,11 +115,13 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
sldi r29,r5,SID_SHIFT - VPN_SHIFT
rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
or r29,r28,r29
-
- /* Calculate hash value for primary slot and store it in r28 */
- rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
- rldicl r0,r3,64-12,48 /* (ea >> 12) & 0xffff */
- xor r28,r5,r0
+ /*
+ * Calculate hash value for primary slot and store it in r28
+ * r3 = va, r5 = vsid
+ * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
+ */
+ rldicl r0,r3,64-12,48
+ xor r28,r5,r0 /* hash */
b 4f
3: /* Calc vpn and put it in r29 */
@@ -130,11 +132,12 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
/*
* calculate hash value for primary slot and
* store it in r28 for 1T segment
+ * r3 = va, r5 = vsid
*/
- rldic r28,r5,25,25 /* (vsid << 25) & 0x7fffffffff */
- clrldi r5,r5,40 /* vsid & 0xffffff */
- rldicl r0,r3,64-12,36 /* (ea >> 12) & 0xfffffff */
- xor r28,r28,r5
+ sldi r28,r5,25 /* vsid << 25 */
+ /* r0 = (va >> 12) & ((1ul << (40 - 12)) -1) */
+ rldicl r0,r3,64-12,36
+ xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
xor r28,r28,r0 /* hash */
/* Convert linux PTE bits into HW equivalents */
@@ -407,11 +410,13 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
*/
rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
or r29,r28,r29
-
- /* Calculate hash value for primary slot and store it in r28 */
- rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
- rldicl r0,r3,64-12,48 /* (ea >> 12) & 0xffff */
- xor r28,r5,r0
+ /*
+ * Calculate hash value for primary slot and store it in r28
+ * r3 = va, r5 = vsid
+ * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
+ */
+ rldicl r0,r3,64-12,48
+ xor r28,r5,r0 /* hash */
b 4f
3: /* Calc vpn and put it in r29 */
@@ -426,11 +431,12 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
/*
* Calculate hash value for primary slot and
* store it in r28 for 1T segment
+ * r3 = va, r5 = vsid
*/
- rldic r28,r5,25,25 /* (vsid << 25) & 0x7fffffffff */
- clrldi r5,r5,40 /* vsid & 0xffffff */
- rldicl r0,r3,64-12,36 /* (ea >> 12) & 0xfffffff */
- xor r28,r28,r5
+ sldi r28,r5,25 /* vsid << 25 */
+ /* r0 = (va >> 12) & ((1ul << (40 - 12)) -1) */
+ rldicl r0,r3,64-12,36
+ xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
xor r28,r28,r0 /* hash */
/* Convert linux PTE bits into HW equivalents */
@@ -752,25 +758,27 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
or r29,r28,r29
- /* Calculate hash value for primary slot and store it in r28 */
- rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
- rldicl r0,r3,64-16,52 /* (ea >> 16) & 0xfff */
- xor r28,r5,r0
+ /* Calculate hash value for primary slot and store it in r28
+ * r3 = va, r5 = vsid
+ * r0 = (va >> 16) & ((1ul << (28 - 16)) -1)
+ */
+ rldicl r0,r3,64-16,52
+ xor r28,r5,r0 /* hash */
b 4f
3: /* Calc vpn and put it in r29 */
sldi r29,r5,SID_SHIFT_1T - VPN_SHIFT
rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT_1T - VPN_SHIFT)
or r29,r28,r29
-
/*
* calculate hash value for primary slot and
* store it in r28 for 1T segment
+ * r3 = va, r5 = vsid
*/
- rldic r28,r5,25,25 /* (vsid << 25) & 0x7fffffffff */
- clrldi r5,r5,40 /* vsid & 0xffffff */
- rldicl r0,r3,64-16,40 /* (ea >> 16) & 0xffffff */
- xor r28,r28,r5
+ sldi r28,r5,25 /* vsid << 25 */
+ /* r0 = (va >> 16) & ((1ul << (40 - 16)) -1) */
+ rldicl r0,r3,64-16,40
+ xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
xor r28,r28,r0 /* hash */
/* Convert linux PTE bits into HW equivalents */
--
1.7.10
^ permalink raw reply related
* Re: [PATCH v6 08/15] memory-hotplug: Common APIs to support page tables hot-remove
From: Simon Jeons @ 2013-01-30 3:27 UTC (permalink / raw)
To: Tang Chen
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <51088298.9080302@cn.fujitsu.com>
On Wed, 2013-01-30 at 10:16 +0800, Tang Chen wrote:
> On 01/29/2013 09:04 PM, Simon Jeons wrote:
> > Hi Tang,
> > On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
> >> From: Wen Congyang<wency@cn.fujitsu.com>
> >>
> >> When memory is removed, the corresponding pagetables should alse be removed.
> >> This patch introduces some common APIs to support vmemmap pagetable and x86_64
> >> architecture pagetable removing.
> >
> > Why don't need to build_all_zonelists like online_pages does during
> > hot-add path(add_memory)?
>
> Hi Simon,
>
> As you said, build_all_zonelists is done by online_pages. When the
> memory device
> is hot-added, we cannot use it. we can only use is when we online the
> pages on it.
Why?
If a node has just one memory device and memory is small, some zone will
not present like zone_highmem, then hot-add another memory device and
zone_highmem appear, if you should build_all_zonelists this time?
>
> But we can online the pages as different types, kernel or movable (which
> belongs to
> different zones), and we can online part of the memory, not all of them.
> So each time we online some pages, we should check if we need to update
> the zone list.
>
> So I think that is why we do build_all_zonelists when online_pages.
> (just my opinion)
>
> Thanks. :)
>
> >
> >>
> >> All pages of virtual mapping in removed memory cannot be freedi if some pages
> >> used as PGD/PUD includes not only removed memory but also other memory. So the
> >> patch uses the following way to check whether page can be freed or not.
> >>
> >> 1. When removing memory, the page structs of the revmoved memory are filled
> >> with 0FD.
> >> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared.
> >> In this case, the page used as PT/PMD can be freed.
> >>
> >> Signed-off-by: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
> >> Signed-off-by: Jianguo Wu<wujianguo@huawei.com>
> >> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>
> >> Signed-off-by: Tang Chen<tangchen@cn.fujitsu.com>
> >> ---
> >> arch/x86/include/asm/pgtable_types.h | 1 +
> >> arch/x86/mm/init_64.c | 299 ++++++++++++++++++++++++++++++++++
> >> arch/x86/mm/pageattr.c | 47 +++---
> >> include/linux/bootmem.h | 1 +
> >> 4 files changed, 326 insertions(+), 22 deletions(-)
> >>
> >> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
> >> index 3c32db8..4b6fd2a 100644
> >> --- a/arch/x86/include/asm/pgtable_types.h
> >> +++ b/arch/x86/include/asm/pgtable_types.h
> >> @@ -352,6 +352,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
> >> * as a pte too.
> >> */
> >> extern pte_t *lookup_address(unsigned long address, unsigned int *level);
> >> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
> >>
> >> #endif /* !__ASSEMBLY__ */
> >>
> >> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> >> index 9ac1723..fe01116 100644
> >> --- a/arch/x86/mm/init_64.c
> >> +++ b/arch/x86/mm/init_64.c
> >> @@ -682,6 +682,305 @@ int arch_add_memory(int nid, u64 start, u64 size)
> >> }
> >> EXPORT_SYMBOL_GPL(arch_add_memory);
> >>
> >> +#define PAGE_INUSE 0xFD
> >> +
> >> +static void __meminit free_pagetable(struct page *page, int order)
> >> +{
> >> + struct zone *zone;
> >> + bool bootmem = false;
> >> + unsigned long magic;
> >> + unsigned int nr_pages = 1<< order;
> >> +
> >> + /* bootmem page has reserved flag */
> >> + if (PageReserved(page)) {
> >> + __ClearPageReserved(page);
> >> + bootmem = true;
> >> +
> >> + magic = (unsigned long)page->lru.next;
> >> + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
> >> + while (nr_pages--)
> >> + put_page_bootmem(page++);
> >> + } else
> >> + __free_pages_bootmem(page, order);
> >> + } else
> >> + free_pages((unsigned long)page_address(page), order);
> >> +
> >> + /*
> >> + * SECTION_INFO pages and MIX_SECTION_INFO pages
> >> + * are all allocated by bootmem.
> >> + */
> >> + if (bootmem) {
> >> + zone = page_zone(page);
> >> + zone_span_writelock(zone);
> >> + zone->present_pages += nr_pages;
> >> + zone_span_writeunlock(zone);
> >> + totalram_pages += nr_pages;
> >> + }
> >> +}
> >> +
> >> +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
> >> +{
> >> + pte_t *pte;
> >> + int i;
> >> +
> >> + for (i = 0; i< PTRS_PER_PTE; i++) {
> >> + pte = pte_start + i;
> >> + if (pte_val(*pte))
> >> + return;
> >> + }
> >> +
> >> + /* free a pte talbe */
> >> + free_pagetable(pmd_page(*pmd), 0);
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pmd_clear(pmd);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +}
> >> +
> >> +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
> >> +{
> >> + pmd_t *pmd;
> >> + int i;
> >> +
> >> + for (i = 0; i< PTRS_PER_PMD; i++) {
> >> + pmd = pmd_start + i;
> >> + if (pmd_val(*pmd))
> >> + return;
> >> + }
> >> +
> >> + /* free a pmd talbe */
> >> + free_pagetable(pud_page(*pud), 0);
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pud_clear(pud);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +}
> >> +
> >> +/* Return true if pgd is changed, otherwise return false. */
> >> +static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
> >> +{
> >> + pud_t *pud;
> >> + int i;
> >> +
> >> + for (i = 0; i< PTRS_PER_PUD; i++) {
> >> + pud = pud_start + i;
> >> + if (pud_val(*pud))
> >> + return false;
> >> + }
> >> +
> >> + /* free a pud table */
> >> + free_pagetable(pgd_page(*pgd), 0);
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pgd_clear(pgd);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +
> >> + return true;
> >> +}
> >> +
> >> +static void __meminit
> >> +remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
> >> + bool direct)
> >> +{
> >> + unsigned long next, pages = 0;
> >> + pte_t *pte;
> >> + void *page_addr;
> >> + phys_addr_t phys_addr;
> >> +
> >> + pte = pte_start + pte_index(addr);
> >> + for (; addr< end; addr = next, pte++) {
> >> + next = (addr + PAGE_SIZE)& PAGE_MASK;
> >> + if (next> end)
> >> + next = end;
> >> +
> >> + if (!pte_present(*pte))
> >> + continue;
> >> +
> >> + /*
> >> + * We mapped [0,1G) memory as identity mapping when
> >> + * initializing, in arch/x86/kernel/head_64.S. These
> >> + * pagetables cannot be removed.
> >> + */
> >> + phys_addr = pte_val(*pte) + (addr& PAGE_MASK);
> >> + if (phys_addr< (phys_addr_t)0x40000000)
> >> + return;
> >> +
> >> + if (IS_ALIGNED(addr, PAGE_SIZE)&&
> >> + IS_ALIGNED(next, PAGE_SIZE)) {
> >> + if (!direct) {
> >> + free_pagetable(pte_page(*pte), 0);
> >> + pages++;
> >> + }
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pte_clear(&init_mm, addr, pte);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + } else {
> >> + /*
> >> + * If we are not removing the whole page, it means
> >> + * other ptes in this page are being used and we canot
> >> + * remove them. So fill the unused ptes with 0xFD, and
> >> + * remove the page when it is wholly filled with 0xFD.
> >> + */
> >> + memset((void *)addr, PAGE_INUSE, next - addr);
> >> + page_addr = page_address(pte_page(*pte));
> >> +
> >> + if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
> >> + free_pagetable(pte_page(*pte), 0);
> >> + pages++;
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pte_clear(&init_mm, addr, pte);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + }
> >> + }
> >> + }
> >> +
> >> + /* Call free_pte_table() in remove_pmd_table(). */
> >> + flush_tlb_all();
> >> + if (direct)
> >> + update_page_count(PG_LEVEL_4K, -pages);
> >> +}
> >> +
> >> +static void __meminit
> >> +remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
> >> + bool direct)
> >> +{
> >> + unsigned long pte_phys, next, pages = 0;
> >> + pte_t *pte_base;
> >> + pmd_t *pmd;
> >> +
> >> + pmd = pmd_start + pmd_index(addr);
> >> + for (; addr< end; addr = next, pmd++) {
> >> + next = pmd_addr_end(addr, end);
> >> +
> >> + if (!pmd_present(*pmd))
> >> + continue;
> >> +
> >> + if (pmd_large(*pmd)) {
> >> + if (IS_ALIGNED(addr, PMD_SIZE)&&
> >> + IS_ALIGNED(next, PMD_SIZE)) {
> >> + if (!direct) {
> >> + free_pagetable(pmd_page(*pmd),
> >> + get_order(PMD_SIZE));
> >> + pages++;
> >> + }
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pmd_clear(pmd);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + continue;
> >> + }
> >> +
> >> + /*
> >> + * We use 2M page, but we need to remove part of them,
> >> + * so split 2M page to 4K page.
> >> + */
> >> + pte_base = (pte_t *)alloc_low_page(&pte_phys);
> >> + BUG_ON(!pte_base);
> >> + __split_large_page((pte_t *)pmd, addr,
> >> + (pte_t *)pte_base);
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +
> >> + flush_tlb_all();
> >> + }
> >> +
> >> + pte_base = (pte_t *)map_low_page((pte_t *)pmd_page_vaddr(*pmd));
> >> + remove_pte_table(pte_base, addr, next, direct);
> >> + free_pte_table(pte_base, pmd);
> >> + unmap_low_page(pte_base);
> >> + }
> >> +
> >> + /* Call free_pmd_table() in remove_pud_table(). */
> >> + if (direct)
> >> + update_page_count(PG_LEVEL_2M, -pages);
> >> +}
> >> +
> >> +static void __meminit
> >> +remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
> >> + bool direct)
> >> +{
> >> + unsigned long pmd_phys, next, pages = 0;
> >> + pmd_t *pmd_base;
> >> + pud_t *pud;
> >> +
> >> + pud = pud_start + pud_index(addr);
> >> + for (; addr< end; addr = next, pud++) {
> >> + next = pud_addr_end(addr, end);
> >> +
> >> + if (!pud_present(*pud))
> >> + continue;
> >> +
> >> + if (pud_large(*pud)) {
> >> + if (IS_ALIGNED(addr, PUD_SIZE)&&
> >> + IS_ALIGNED(next, PUD_SIZE)) {
> >> + if (!direct) {
> >> + free_pagetable(pud_page(*pud),
> >> + get_order(PUD_SIZE));
> >> + pages++;
> >> + }
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pud_clear(pud);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + continue;
> >> + }
> >> +
> >> + /*
> >> + * We use 1G page, but we need to remove part of them,
> >> + * so split 1G page to 2M page.
> >> + */
> >> + pmd_base = (pmd_t *)alloc_low_page(&pmd_phys);
> >> + BUG_ON(!pmd_base);
> >> + __split_large_page((pte_t *)pud, addr,
> >> + (pte_t *)pmd_base);
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pud_populate(&init_mm, pud, __va(pmd_phys));
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +
> >> + flush_tlb_all();
> >> + }
> >> +
> >> + pmd_base = (pmd_t *)map_low_page((pmd_t *)pud_page_vaddr(*pud));
> >> + remove_pmd_table(pmd_base, addr, next, direct);
> >> + free_pmd_table(pmd_base, pud);
> >> + unmap_low_page(pmd_base);
> >> + }
> >> +
> >> + if (direct)
> >> + update_page_count(PG_LEVEL_1G, -pages);
> >> +}
> >> +
> >> +/* start and end are both virtual address. */
> >> +static void __meminit
> >> +remove_pagetable(unsigned long start, unsigned long end, bool direct)
> >> +{
> >> + unsigned long next;
> >> + pgd_t *pgd;
> >> + pud_t *pud;
> >> + bool pgd_changed = false;
> >> +
> >> + for (; start< end; start = next) {
> >> + pgd = pgd_offset_k(start);
> >> + if (!pgd_present(*pgd))
> >> + continue;
> >> +
> >> + next = pgd_addr_end(start, end);
> >> +
> >> + pud = (pud_t *)map_low_page((pud_t *)pgd_page_vaddr(*pgd));
> >> + remove_pud_table(pud, start, next, direct);
> >> + if (free_pud_table(pud, pgd))
> >> + pgd_changed = true;
> >> + unmap_low_page(pud);
> >> + }
> >> +
> >> + if (pgd_changed)
> >> + sync_global_pgds(start, end - 1);
> >> +
> >> + flush_tlb_all();
> >> +}
> >> +
> >> #ifdef CONFIG_MEMORY_HOTREMOVE
> >> int __ref arch_remove_memory(u64 start, u64 size)
> >> {
> >> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
> >> index a718e0d..7dcb6f9 100644
> >> --- a/arch/x86/mm/pageattr.c
> >> +++ b/arch/x86/mm/pageattr.c
> >> @@ -501,21 +501,13 @@ out_unlock:
> >> return do_split;
> >> }
> >>
> >> -static int split_large_page(pte_t *kpte, unsigned long address)
> >> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
> >> {
> >> unsigned long pfn, pfninc = 1;
> >> unsigned int i, level;
> >> - pte_t *pbase, *tmp;
> >> + pte_t *tmp;
> >> pgprot_t ref_prot;
> >> - struct page *base;
> >> -
> >> - if (!debug_pagealloc)
> >> - spin_unlock(&cpa_lock);
> >> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
> >> - if (!debug_pagealloc)
> >> - spin_lock(&cpa_lock);
> >> - if (!base)
> >> - return -ENOMEM;
> >> + struct page *base = virt_to_page(pbase);
> >>
> >> spin_lock(&pgd_lock);
> >> /*
> >> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
> >> * up for us already:
> >> */
> >> tmp = lookup_address(address,&level);
> >> - if (tmp != kpte)
> >> - goto out_unlock;
> >> + if (tmp != kpte) {
> >> + spin_unlock(&pgd_lock);
> >> + return 1;
> >> + }
> >>
> >> - pbase = (pte_t *)page_address(base);
> >> paravirt_alloc_pte(&init_mm, page_to_pfn(base));
> >> ref_prot = pte_pgprot(pte_clrhuge(*kpte));
> >> /*
> >> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
> >> * going on.
> >> */
> >> __flush_tlb_all();
> >> + spin_unlock(&pgd_lock);
> >>
> >> - base = NULL;
> >> + return 0;
> >> +}
> >>
> >> -out_unlock:
> >> - /*
> >> - * If we dropped out via the lookup_address check under
> >> - * pgd_lock then stick the page back into the pool:
> >> - */
> >> - if (base)
> >> +static int split_large_page(pte_t *kpte, unsigned long address)
> >> +{
> >> + pte_t *pbase;
> >> + struct page *base;
> >> +
> >> + if (!debug_pagealloc)
> >> + spin_unlock(&cpa_lock);
> >> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
> >> + if (!debug_pagealloc)
> >> + spin_lock(&cpa_lock);
> >> + if (!base)
> >> + return -ENOMEM;
> >> +
> >> + pbase = (pte_t *)page_address(base);
> >> + if (__split_large_page(kpte, address, pbase))
> >> __free_page(base);
> >> - spin_unlock(&pgd_lock);
> >>
> >> return 0;
> >> }
> >> diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
> >> index 3f778c2..190ff06 100644
> >> --- a/include/linux/bootmem.h
> >> +++ b/include/linux/bootmem.h
> >> @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
> >> unsigned long size);
> >> extern void free_bootmem(unsigned long physaddr, unsigned long size);
> >> extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
> >> +extern void __free_pages_bootmem(struct page *page, unsigned int order);
> >>
> >> /*
> >> * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
> >
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply
* Re: [PATCH v6 00/15] memory-hotplug: hot-remove physical memory
From: Tang Chen @ 2013-01-30 3:00 UTC (permalink / raw)
To: Simon Jeons
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <1359514113.1288.2.camel@kernel>
On 01/30/2013 10:48 AM, Simon Jeons wrote:
> On Wed, 2013-01-30 at 10:32 +0800, Tang Chen wrote:
>> On 01/29/2013 08:52 PM, Simon Jeons wrote:
>>> Hi Tang,
>>>
>>> On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
>>>> Here is the physical memory hot-remove patch-set based on 3.8rc-2.
>>
>> Hi Simon,
>>
>> I'll summarize all the info and answer you later. :)
>>
>> Thanks for asking. :)
>
> Thanks Tang, IIRC, there's qemu feature support memory hot-add/remove
> emulation if we don't have machine which supports memory hot-add/remove
> to test. Is that qemu feature merged? Otherwise where can I get that
> patchset?
Hi Simon,
There are patches to support hot-add/remove in qemu, but they are not
merged yet.
You can get the latest patches here:
http://lists.nongnu.org/archive/html/qemu-devel/2012-12/msg02693.html
BTY, it is unstable and full of problems, and you need to compile your
own seabios too.
Thanks. :)
>
>>
>>>
>>> Some questions ask you, not has relationship with this patchset, but is
>>> memory hotplug stuff.
>>>
>>> 1. In function node_states_check_changes_online:
>>>
>>> comments:
>>> * If we don't have HIGHMEM nor movable node,
>>> * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
>>> * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
>>>
>>> How to understand it? Why we don't have HIGHMEM nor movable node and
>>> node_staes[N_NORMAL_MEMORY] contains 0...ZONE_MOVABLE, IIUC,
>>> N_NORMAL_MEMORY only means the node has regular memory.
>>>
>>> * If we don't have movable node, node_states[N_NORMAL_MEMORY]
>>> * contains nodes which have zones of 0...ZONE_MOVABLE,
>>> * set zone_last to ZONE_MOVABLE.
>>>
>>> How to understand?
>>>
>>> 2. In function move_pfn_range_left, why end<= z2->zone_start_pfn is not
>>> correct? The comments said that must include/overlap, why?
>>>
>>> 3. In function online_pages, the normal case(w/o online_kenrel,
>>> online_movable), why not check if the new zone is overlap with adjacent
>>> zones?
>>>
>>> 4. Could you summarize the difference implementation between hot-add and
>>> logic-add, hot-remove and logic-remove?
>>>
>>>
>>>>
>>>> This patch-set aims to implement physical memory hot-removing.
>>>>
>>>> The patches can free/remove the following things:
>>>>
>>>> - /sys/firmware/memmap/X/{end, start, type} : [PATCH 4/15]
>>>> - memmap of sparse-vmemmap : [PATCH 6,7,8,10/15]
>>>> - page table of removed memory : [RFC PATCH 7,8,10/15]
>>>> - node and related sysfs files : [RFC PATCH 13-15/15]
>>>>
>>>>
>>>> Existing problem:
>>>> If CONFIG_MEMCG is selected, we will allocate memory to store page cgroup
>>>> when we online pages.
>>>>
>>>> For example: there is a memory device on node 1. The address range
>>>> is [1G, 1.5G). You will find 4 new directories memory8, memory9, memory10,
>>>> and memory11 under the directory /sys/devices/system/memory/.
>>>>
>>>> If CONFIG_MEMCG is selected, when we online memory8, the memory stored page
>>>> cgroup is not provided by this memory device. But when we online memory9, the
>>>> memory stored page cgroup may be provided by memory8. So we can't offline
>>>> memory8 now. We should offline the memory in the reversed order.
>>>>
>>>> When the memory device is hotremoved, we will auto offline memory provided
>>>> by this memory device. But we don't know which memory is onlined first, so
>>>> offlining memory may fail.
>>>>
>>>> In patch1, we provide a solution which is not good enough:
>>>> Iterate twice to offline the memory.
>>>> 1st iterate: offline every non primary memory block.
>>>> 2nd iterate: offline primary (i.e. first added) memory block.
>>>>
>>>> And a new idea from Wen Congyang<wency@cn.fujitsu.com> is:
>>>> allocate the memory from the memory block they are describing.
>>>>
>>>> But we are not sure if it is OK to do so because there is not existing API
>>>> to do so, and we need to move page_cgroup memory allocation from MEM_GOING_ONLINE
>>>> to MEM_ONLINE. And also, it may interfere the hugepage.
>>>>
>>>>
>>>>
>>>> How to test this patchset?
>>>> 1. apply this patchset and build the kernel. MEMORY_HOTPLUG, MEMORY_HOTREMOVE,
>>>> ACPI_HOTPLUG_MEMORY must be selected.
>>>> 2. load the module acpi_memhotplug
>>>> 3. hotplug the memory device(it depends on your hardware)
>>>> You will see the memory device under the directory /sys/bus/acpi/devices/.
>>>> Its name is PNP0C80:XX.
>>>> 4. online/offline pages provided by this memory device
>>>> You can write online/offline to /sys/devices/system/memory/memoryX/state to
>>>> online/offline pages provided by this memory device
>>>> 5. hotremove the memory device
>>>> You can hotremove the memory device by the hardware, or writing 1 to
>>>> /sys/bus/acpi/devices/PNP0C80:XX/eject.
>>>
>>> Is there a similar knode to hot-add the memory device?
>>>
>>>>
>>>>
>>>> Note: if the memory provided by the memory device is used by the kernel, it
>>>> can't be offlined. It is not a bug.
>>>>
>>>>
>>>> Changelogs from v5 to v6:
>>>> Patch3: Add some more comments to explain memory hot-remove.
>>>> Patch4: Remove bootmem member in struct firmware_map_entry.
>>>> Patch6: Repeatedly register bootmem pages when using hugepage.
>>>> Patch8: Repeatedly free bootmem pages when using hugepage.
>>>> Patch14: Don't free pgdat when offlining a node, just reset it to 0.
>>>> Patch15: New patch, pgdat is not freed in patch14, so don't allocate a new
>>>> one when online a node.
>>>>
>>>> Changelogs from v4 to v5:
>>>> Patch7: new patch, move pgdat_resize_lock into sparse_remove_one_section() to
>>>> avoid disabling irq because we need flush tlb when free pagetables.
>>>> Patch8: new patch, pick up some common APIs that are used to free direct mapping
>>>> and vmemmap pagetables.
>>>> Patch9: free direct mapping pagetables on x86_64 arch.
>>>> Patch10: free vmemmap pagetables.
>>>> Patch11: since freeing memmap with vmemmap has been implemented, the config
>>>> macro CONFIG_SPARSEMEM_VMEMMAP when defining __remove_section() is
>>>> no longer needed.
>>>> Patch13: no need to modify acpi_memory_disable_device() since it was removed,
>>>> and add nid parameter when calling remove_memory().
>>>>
>>>> Changelogs from v3 to v4:
>>>> Patch7: remove unused codes.
>>>> Patch8: fix nr_pages that is passed to free_map_bootmem()
>>>>
>>>> Changelogs from v2 to v3:
>>>> Patch9: call sync_global_pgds() if pgd is changed
>>>> Patch10: fix a problem int the patch
>>>>
>>>> Changelogs from v1 to v2:
>>>> Patch1: new patch, offline memory twice. 1st iterate: offline every non primary
>>>> memory block. 2nd iterate: offline primary (i.e. first added) memory
>>>> block.
>>>>
>>>> Patch3: new patch, no logical change, just remove reduntant codes.
>>>>
>>>> Patch9: merge the patch from wujianguo into this patch. flush tlb on all cpu
>>>> after the pagetable is changed.
>>>>
>>>> Patch12: new patch, free node_data when a node is offlined.
>>>>
>>>>
>>>> Tang Chen (6):
>>>> memory-hotplug: move pgdat_resize_lock into
>>>> sparse_remove_one_section()
>>>> memory-hotplug: remove page table of x86_64 architecture
>>>> memory-hotplug: remove memmap of sparse-vmemmap
>>>> memory-hotplug: Integrated __remove_section() of
>>>> CONFIG_SPARSEMEM_VMEMMAP.
>>>> memory-hotplug: remove sysfs file of node
>>>> memory-hotplug: Do not allocate pdgat if it was not freed when
>>>> offline.
>>>>
>>>> Wen Congyang (5):
>>>> memory-hotplug: try to offline the memory twice to avoid dependence
>>>> memory-hotplug: remove redundant codes
>>>> memory-hotplug: introduce new function arch_remove_memory() for
>>>> removing page table depends on architecture
>>>> memory-hotplug: Common APIs to support page tables hot-remove
>>>> memory-hotplug: free node_data when a node is offlined
>>>>
>>>> Yasuaki Ishimatsu (4):
>>>> memory-hotplug: check whether all memory blocks are offlined or not
>>>> when removing memory
>>>> memory-hotplug: remove /sys/firmware/memmap/X sysfs
>>>> memory-hotplug: implement register_page_bootmem_info_section of
>>>> sparse-vmemmap
>>>> memory-hotplug: memory_hotplug: clear zone when removing the memory
>>>>
>>>> arch/arm64/mm/mmu.c | 3 +
>>>> arch/ia64/mm/discontig.c | 10 +
>>>> arch/ia64/mm/init.c | 18 ++
>>>> arch/powerpc/mm/init_64.c | 10 +
>>>> arch/powerpc/mm/mem.c | 12 +
>>>> arch/s390/mm/init.c | 12 +
>>>> arch/s390/mm/vmem.c | 10 +
>>>> arch/sh/mm/init.c | 17 ++
>>>> arch/sparc/mm/init_64.c | 10 +
>>>> arch/tile/mm/init.c | 8 +
>>>> arch/x86/include/asm/pgtable_types.h | 1 +
>>>> arch/x86/mm/init_32.c | 12 +
>>>> arch/x86/mm/init_64.c | 390 +++++++++++++++++++++++++++++
>>>> arch/x86/mm/pageattr.c | 47 ++--
>>>> drivers/acpi/acpi_memhotplug.c | 8 +-
>>>> drivers/base/memory.c | 6 +
>>>> drivers/firmware/memmap.c | 96 +++++++-
>>>> include/linux/bootmem.h | 1 +
>>>> include/linux/firmware-map.h | 6 +
>>>> include/linux/memory_hotplug.h | 15 +-
>>>> include/linux/mm.h | 4 +-
>>>> mm/memory_hotplug.c | 459 +++++++++++++++++++++++++++++++---
>>>> mm/sparse.c | 8 +-
>>>> 23 files changed, 1094 insertions(+), 69 deletions(-)
>>>>
>>>> --
>>>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>>>> the body to majordomo@kvack.org. For more info on Linux MM,
>>>> see: http://www.linux-mm.org/ .
>>>> Don't email:<a href=mailto:"dont@kvack.org"> email@kvack.org</a>
>>>
>>>
>>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply
* Re: [PATCH v6 00/15] memory-hotplug: hot-remove physical memory
From: Simon Jeons @ 2013-01-30 2:48 UTC (permalink / raw)
To: Tang Chen
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <5108864B.6040804@cn.fujitsu.com>
On Wed, 2013-01-30 at 10:32 +0800, Tang Chen wrote:
> On 01/29/2013 08:52 PM, Simon Jeons wrote:
> > Hi Tang,
> >
> > On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
> >> Here is the physical memory hot-remove patch-set based on 3.8rc-2.
>
> Hi Simon,
>
> I'll summarize all the info and answer you later. :)
>
> Thanks for asking. :)
Thanks Tang, IIRC, there's qemu feature support memory hot-add/remove
emulation if we don't have machine which supports memory hot-add/remove
to test. Is that qemu feature merged? Otherwise where can I get that
patchset?
>
> >
> > Some questions ask you, not has relationship with this patchset, but is
> > memory hotplug stuff.
> >
> > 1. In function node_states_check_changes_online:
> >
> > comments:
> > * If we don't have HIGHMEM nor movable node,
> > * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
> > * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
> >
> > How to understand it? Why we don't have HIGHMEM nor movable node and
> > node_staes[N_NORMAL_MEMORY] contains 0...ZONE_MOVABLE, IIUC,
> > N_NORMAL_MEMORY only means the node has regular memory.
> >
> > * If we don't have movable node, node_states[N_NORMAL_MEMORY]
> > * contains nodes which have zones of 0...ZONE_MOVABLE,
> > * set zone_last to ZONE_MOVABLE.
> >
> > How to understand?
> >
> > 2. In function move_pfn_range_left, why end<= z2->zone_start_pfn is not
> > correct? The comments said that must include/overlap, why?
> >
> > 3. In function online_pages, the normal case(w/o online_kenrel,
> > online_movable), why not check if the new zone is overlap with adjacent
> > zones?
> >
> > 4. Could you summarize the difference implementation between hot-add and
> > logic-add, hot-remove and logic-remove?
> >
> >
> >>
> >> This patch-set aims to implement physical memory hot-removing.
> >>
> >> The patches can free/remove the following things:
> >>
> >> - /sys/firmware/memmap/X/{end, start, type} : [PATCH 4/15]
> >> - memmap of sparse-vmemmap : [PATCH 6,7,8,10/15]
> >> - page table of removed memory : [RFC PATCH 7,8,10/15]
> >> - node and related sysfs files : [RFC PATCH 13-15/15]
> >>
> >>
> >> Existing problem:
> >> If CONFIG_MEMCG is selected, we will allocate memory to store page cgroup
> >> when we online pages.
> >>
> >> For example: there is a memory device on node 1. The address range
> >> is [1G, 1.5G). You will find 4 new directories memory8, memory9, memory10,
> >> and memory11 under the directory /sys/devices/system/memory/.
> >>
> >> If CONFIG_MEMCG is selected, when we online memory8, the memory stored page
> >> cgroup is not provided by this memory device. But when we online memory9, the
> >> memory stored page cgroup may be provided by memory8. So we can't offline
> >> memory8 now. We should offline the memory in the reversed order.
> >>
> >> When the memory device is hotremoved, we will auto offline memory provided
> >> by this memory device. But we don't know which memory is onlined first, so
> >> offlining memory may fail.
> >>
> >> In patch1, we provide a solution which is not good enough:
> >> Iterate twice to offline the memory.
> >> 1st iterate: offline every non primary memory block.
> >> 2nd iterate: offline primary (i.e. first added) memory block.
> >>
> >> And a new idea from Wen Congyang<wency@cn.fujitsu.com> is:
> >> allocate the memory from the memory block they are describing.
> >>
> >> But we are not sure if it is OK to do so because there is not existing API
> >> to do so, and we need to move page_cgroup memory allocation from MEM_GOING_ONLINE
> >> to MEM_ONLINE. And also, it may interfere the hugepage.
> >>
> >>
> >>
> >> How to test this patchset?
> >> 1. apply this patchset and build the kernel. MEMORY_HOTPLUG, MEMORY_HOTREMOVE,
> >> ACPI_HOTPLUG_MEMORY must be selected.
> >> 2. load the module acpi_memhotplug
> >> 3. hotplug the memory device(it depends on your hardware)
> >> You will see the memory device under the directory /sys/bus/acpi/devices/.
> >> Its name is PNP0C80:XX.
> >> 4. online/offline pages provided by this memory device
> >> You can write online/offline to /sys/devices/system/memory/memoryX/state to
> >> online/offline pages provided by this memory device
> >> 5. hotremove the memory device
> >> You can hotremove the memory device by the hardware, or writing 1 to
> >> /sys/bus/acpi/devices/PNP0C80:XX/eject.
> >
> > Is there a similar knode to hot-add the memory device?
> >
> >>
> >>
> >> Note: if the memory provided by the memory device is used by the kernel, it
> >> can't be offlined. It is not a bug.
> >>
> >>
> >> Changelogs from v5 to v6:
> >> Patch3: Add some more comments to explain memory hot-remove.
> >> Patch4: Remove bootmem member in struct firmware_map_entry.
> >> Patch6: Repeatedly register bootmem pages when using hugepage.
> >> Patch8: Repeatedly free bootmem pages when using hugepage.
> >> Patch14: Don't free pgdat when offlining a node, just reset it to 0.
> >> Patch15: New patch, pgdat is not freed in patch14, so don't allocate a new
> >> one when online a node.
> >>
> >> Changelogs from v4 to v5:
> >> Patch7: new patch, move pgdat_resize_lock into sparse_remove_one_section() to
> >> avoid disabling irq because we need flush tlb when free pagetables.
> >> Patch8: new patch, pick up some common APIs that are used to free direct mapping
> >> and vmemmap pagetables.
> >> Patch9: free direct mapping pagetables on x86_64 arch.
> >> Patch10: free vmemmap pagetables.
> >> Patch11: since freeing memmap with vmemmap has been implemented, the config
> >> macro CONFIG_SPARSEMEM_VMEMMAP when defining __remove_section() is
> >> no longer needed.
> >> Patch13: no need to modify acpi_memory_disable_device() since it was removed,
> >> and add nid parameter when calling remove_memory().
> >>
> >> Changelogs from v3 to v4:
> >> Patch7: remove unused codes.
> >> Patch8: fix nr_pages that is passed to free_map_bootmem()
> >>
> >> Changelogs from v2 to v3:
> >> Patch9: call sync_global_pgds() if pgd is changed
> >> Patch10: fix a problem int the patch
> >>
> >> Changelogs from v1 to v2:
> >> Patch1: new patch, offline memory twice. 1st iterate: offline every non primary
> >> memory block. 2nd iterate: offline primary (i.e. first added) memory
> >> block.
> >>
> >> Patch3: new patch, no logical change, just remove reduntant codes.
> >>
> >> Patch9: merge the patch from wujianguo into this patch. flush tlb on all cpu
> >> after the pagetable is changed.
> >>
> >> Patch12: new patch, free node_data when a node is offlined.
> >>
> >>
> >> Tang Chen (6):
> >> memory-hotplug: move pgdat_resize_lock into
> >> sparse_remove_one_section()
> >> memory-hotplug: remove page table of x86_64 architecture
> >> memory-hotplug: remove memmap of sparse-vmemmap
> >> memory-hotplug: Integrated __remove_section() of
> >> CONFIG_SPARSEMEM_VMEMMAP.
> >> memory-hotplug: remove sysfs file of node
> >> memory-hotplug: Do not allocate pdgat if it was not freed when
> >> offline.
> >>
> >> Wen Congyang (5):
> >> memory-hotplug: try to offline the memory twice to avoid dependence
> >> memory-hotplug: remove redundant codes
> >> memory-hotplug: introduce new function arch_remove_memory() for
> >> removing page table depends on architecture
> >> memory-hotplug: Common APIs to support page tables hot-remove
> >> memory-hotplug: free node_data when a node is offlined
> >>
> >> Yasuaki Ishimatsu (4):
> >> memory-hotplug: check whether all memory blocks are offlined or not
> >> when removing memory
> >> memory-hotplug: remove /sys/firmware/memmap/X sysfs
> >> memory-hotplug: implement register_page_bootmem_info_section of
> >> sparse-vmemmap
> >> memory-hotplug: memory_hotplug: clear zone when removing the memory
> >>
> >> arch/arm64/mm/mmu.c | 3 +
> >> arch/ia64/mm/discontig.c | 10 +
> >> arch/ia64/mm/init.c | 18 ++
> >> arch/powerpc/mm/init_64.c | 10 +
> >> arch/powerpc/mm/mem.c | 12 +
> >> arch/s390/mm/init.c | 12 +
> >> arch/s390/mm/vmem.c | 10 +
> >> arch/sh/mm/init.c | 17 ++
> >> arch/sparc/mm/init_64.c | 10 +
> >> arch/tile/mm/init.c | 8 +
> >> arch/x86/include/asm/pgtable_types.h | 1 +
> >> arch/x86/mm/init_32.c | 12 +
> >> arch/x86/mm/init_64.c | 390 +++++++++++++++++++++++++++++
> >> arch/x86/mm/pageattr.c | 47 ++--
> >> drivers/acpi/acpi_memhotplug.c | 8 +-
> >> drivers/base/memory.c | 6 +
> >> drivers/firmware/memmap.c | 96 +++++++-
> >> include/linux/bootmem.h | 1 +
> >> include/linux/firmware-map.h | 6 +
> >> include/linux/memory_hotplug.h | 15 +-
> >> include/linux/mm.h | 4 +-
> >> mm/memory_hotplug.c | 459 +++++++++++++++++++++++++++++++---
> >> mm/sparse.c | 8 +-
> >> 23 files changed, 1094 insertions(+), 69 deletions(-)
> >>
> >> --
> >> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> >> the body to majordomo@kvack.org. For more info on Linux MM,
> >> see: http://www.linux-mm.org/ .
> >> Don't email:<a href=mailto:"dont@kvack.org"> email@kvack.org</a>
> >
> >
> >
^ permalink raw reply
* Re: [PATCH v6 00/15] memory-hotplug: hot-remove physical memory
From: Tang Chen @ 2013-01-30 2:32 UTC (permalink / raw)
To: Simon Jeons
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <1359463973.1624.15.camel@kernel>
On 01/29/2013 08:52 PM, Simon Jeons wrote:
> Hi Tang,
>
> On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
>> Here is the physical memory hot-remove patch-set based on 3.8rc-2.
Hi Simon,
I'll summarize all the info and answer you later. :)
Thanks for asking. :)
>
> Some questions ask you, not has relationship with this patchset, but is
> memory hotplug stuff.
>
> 1. In function node_states_check_changes_online:
>
> comments:
> * If we don't have HIGHMEM nor movable node,
> * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
> * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
>
> How to understand it? Why we don't have HIGHMEM nor movable node and
> node_staes[N_NORMAL_MEMORY] contains 0...ZONE_MOVABLE, IIUC,
> N_NORMAL_MEMORY only means the node has regular memory.
>
> * If we don't have movable node, node_states[N_NORMAL_MEMORY]
> * contains nodes which have zones of 0...ZONE_MOVABLE,
> * set zone_last to ZONE_MOVABLE.
>
> How to understand?
>
> 2. In function move_pfn_range_left, why end<= z2->zone_start_pfn is not
> correct? The comments said that must include/overlap, why?
>
> 3. In function online_pages, the normal case(w/o online_kenrel,
> online_movable), why not check if the new zone is overlap with adjacent
> zones?
>
> 4. Could you summarize the difference implementation between hot-add and
> logic-add, hot-remove and logic-remove?
>
>
>>
>> This patch-set aims to implement physical memory hot-removing.
>>
>> The patches can free/remove the following things:
>>
>> - /sys/firmware/memmap/X/{end, start, type} : [PATCH 4/15]
>> - memmap of sparse-vmemmap : [PATCH 6,7,8,10/15]
>> - page table of removed memory : [RFC PATCH 7,8,10/15]
>> - node and related sysfs files : [RFC PATCH 13-15/15]
>>
>>
>> Existing problem:
>> If CONFIG_MEMCG is selected, we will allocate memory to store page cgroup
>> when we online pages.
>>
>> For example: there is a memory device on node 1. The address range
>> is [1G, 1.5G). You will find 4 new directories memory8, memory9, memory10,
>> and memory11 under the directory /sys/devices/system/memory/.
>>
>> If CONFIG_MEMCG is selected, when we online memory8, the memory stored page
>> cgroup is not provided by this memory device. But when we online memory9, the
>> memory stored page cgroup may be provided by memory8. So we can't offline
>> memory8 now. We should offline the memory in the reversed order.
>>
>> When the memory device is hotremoved, we will auto offline memory provided
>> by this memory device. But we don't know which memory is onlined first, so
>> offlining memory may fail.
>>
>> In patch1, we provide a solution which is not good enough:
>> Iterate twice to offline the memory.
>> 1st iterate: offline every non primary memory block.
>> 2nd iterate: offline primary (i.e. first added) memory block.
>>
>> And a new idea from Wen Congyang<wency@cn.fujitsu.com> is:
>> allocate the memory from the memory block they are describing.
>>
>> But we are not sure if it is OK to do so because there is not existing API
>> to do so, and we need to move page_cgroup memory allocation from MEM_GOING_ONLINE
>> to MEM_ONLINE. And also, it may interfere the hugepage.
>>
>>
>>
>> How to test this patchset?
>> 1. apply this patchset and build the kernel. MEMORY_HOTPLUG, MEMORY_HOTREMOVE,
>> ACPI_HOTPLUG_MEMORY must be selected.
>> 2. load the module acpi_memhotplug
>> 3. hotplug the memory device(it depends on your hardware)
>> You will see the memory device under the directory /sys/bus/acpi/devices/.
>> Its name is PNP0C80:XX.
>> 4. online/offline pages provided by this memory device
>> You can write online/offline to /sys/devices/system/memory/memoryX/state to
>> online/offline pages provided by this memory device
>> 5. hotremove the memory device
>> You can hotremove the memory device by the hardware, or writing 1 to
>> /sys/bus/acpi/devices/PNP0C80:XX/eject.
>
> Is there a similar knode to hot-add the memory device?
>
>>
>>
>> Note: if the memory provided by the memory device is used by the kernel, it
>> can't be offlined. It is not a bug.
>>
>>
>> Changelogs from v5 to v6:
>> Patch3: Add some more comments to explain memory hot-remove.
>> Patch4: Remove bootmem member in struct firmware_map_entry.
>> Patch6: Repeatedly register bootmem pages when using hugepage.
>> Patch8: Repeatedly free bootmem pages when using hugepage.
>> Patch14: Don't free pgdat when offlining a node, just reset it to 0.
>> Patch15: New patch, pgdat is not freed in patch14, so don't allocate a new
>> one when online a node.
>>
>> Changelogs from v4 to v5:
>> Patch7: new patch, move pgdat_resize_lock into sparse_remove_one_section() to
>> avoid disabling irq because we need flush tlb when free pagetables.
>> Patch8: new patch, pick up some common APIs that are used to free direct mapping
>> and vmemmap pagetables.
>> Patch9: free direct mapping pagetables on x86_64 arch.
>> Patch10: free vmemmap pagetables.
>> Patch11: since freeing memmap with vmemmap has been implemented, the config
>> macro CONFIG_SPARSEMEM_VMEMMAP when defining __remove_section() is
>> no longer needed.
>> Patch13: no need to modify acpi_memory_disable_device() since it was removed,
>> and add nid parameter when calling remove_memory().
>>
>> Changelogs from v3 to v4:
>> Patch7: remove unused codes.
>> Patch8: fix nr_pages that is passed to free_map_bootmem()
>>
>> Changelogs from v2 to v3:
>> Patch9: call sync_global_pgds() if pgd is changed
>> Patch10: fix a problem int the patch
>>
>> Changelogs from v1 to v2:
>> Patch1: new patch, offline memory twice. 1st iterate: offline every non primary
>> memory block. 2nd iterate: offline primary (i.e. first added) memory
>> block.
>>
>> Patch3: new patch, no logical change, just remove reduntant codes.
>>
>> Patch9: merge the patch from wujianguo into this patch. flush tlb on all cpu
>> after the pagetable is changed.
>>
>> Patch12: new patch, free node_data when a node is offlined.
>>
>>
>> Tang Chen (6):
>> memory-hotplug: move pgdat_resize_lock into
>> sparse_remove_one_section()
>> memory-hotplug: remove page table of x86_64 architecture
>> memory-hotplug: remove memmap of sparse-vmemmap
>> memory-hotplug: Integrated __remove_section() of
>> CONFIG_SPARSEMEM_VMEMMAP.
>> memory-hotplug: remove sysfs file of node
>> memory-hotplug: Do not allocate pdgat if it was not freed when
>> offline.
>>
>> Wen Congyang (5):
>> memory-hotplug: try to offline the memory twice to avoid dependence
>> memory-hotplug: remove redundant codes
>> memory-hotplug: introduce new function arch_remove_memory() for
>> removing page table depends on architecture
>> memory-hotplug: Common APIs to support page tables hot-remove
>> memory-hotplug: free node_data when a node is offlined
>>
>> Yasuaki Ishimatsu (4):
>> memory-hotplug: check whether all memory blocks are offlined or not
>> when removing memory
>> memory-hotplug: remove /sys/firmware/memmap/X sysfs
>> memory-hotplug: implement register_page_bootmem_info_section of
>> sparse-vmemmap
>> memory-hotplug: memory_hotplug: clear zone when removing the memory
>>
>> arch/arm64/mm/mmu.c | 3 +
>> arch/ia64/mm/discontig.c | 10 +
>> arch/ia64/mm/init.c | 18 ++
>> arch/powerpc/mm/init_64.c | 10 +
>> arch/powerpc/mm/mem.c | 12 +
>> arch/s390/mm/init.c | 12 +
>> arch/s390/mm/vmem.c | 10 +
>> arch/sh/mm/init.c | 17 ++
>> arch/sparc/mm/init_64.c | 10 +
>> arch/tile/mm/init.c | 8 +
>> arch/x86/include/asm/pgtable_types.h | 1 +
>> arch/x86/mm/init_32.c | 12 +
>> arch/x86/mm/init_64.c | 390 +++++++++++++++++++++++++++++
>> arch/x86/mm/pageattr.c | 47 ++--
>> drivers/acpi/acpi_memhotplug.c | 8 +-
>> drivers/base/memory.c | 6 +
>> drivers/firmware/memmap.c | 96 +++++++-
>> include/linux/bootmem.h | 1 +
>> include/linux/firmware-map.h | 6 +
>> include/linux/memory_hotplug.h | 15 +-
>> include/linux/mm.h | 4 +-
>> mm/memory_hotplug.c | 459 +++++++++++++++++++++++++++++++---
>> mm/sparse.c | 8 +-
>> 23 files changed, 1094 insertions(+), 69 deletions(-)
>>
>> --
>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>> the body to majordomo@kvack.org. For more info on Linux MM,
>> see: http://www.linux-mm.org/ .
>> Don't email:<a href=mailto:"dont@kvack.org"> email@kvack.org</a>
>
>
>
^ permalink raw reply
* Re: PREMPT_RT
From: Vineeth @ 2013-01-30 2:29 UTC (permalink / raw)
To: linuxppc-dev
In-Reply-To: <CAFbQSaCxSVDRW=kcjkrbrm=8Sy4N0q29ALfqb4o3UdB3crY64g@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1174 bytes --]
Hi,
I've added a VDSO patch on my 2.6.32 kernel. When i enabled PREMPT_RT i am
getting the below oops messages.
What is the reason for this ? When googled, it was mentioned in many places
that it is caused by the get_cpu()/put_cpu() preempt disabled region.
Can someone help me to understand this ?
BUG: sleeping function called from invalid context at kernel/rtmutex.c:684
pcnt: 10002 0 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper
Call Trace:
[c0771d40] [c000750c] show_stack+0x44/0x160 (unreliable)
[c0771d70] [c0021114] __might_sleep+0xe4/0x108
[c0771d80] [c05700bc] rt_spin_lock+0x38/0xb4
[c0771d90] [c005a3b0] ntp_tick_length+0x20/0x54
[c0771db0] [c00594e8] update_wall_time+0xb0/0xa3c
[c0771e20] [c0040bc0] do_timer+0x38/0x4c
[c0771e30] [c005f2c4] tick_do_update_jiffies64+0x1cc/0x2a8
[c0771e70] [c005f494] tick_check_idle+0xf4/0x120
[c0771ea0] [c0039a50] irq_enter+0x68/0x7c
[c0771eb0] [c000ae78] timer_interrupt+0xb0/0x168
[c0771ed0] [c000e84c] ret_from_except+0x0/0x18
[c0771f90] [c000874c] cpu_idle+0x58/0xf4
[c0771fb0] [c0002330] rest_init+0xa0/0xb0
[c0771fc0] [c06fc9d4] start_kernel+0x320/0x334
[c0771ff0] [c00003f0] skpinv+0x308/0x344
Thanks
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^ permalink raw reply
* PREMPT_RT
From: Vineeth @ 2013-01-30 2:19 UTC (permalink / raw)
To: linuxppc-dev
In-Reply-To: <CAFbQSaBm-0ROHX80JQN6ef4Hgy1PgH8PmYRSRpyJ1+mNo+HnbQ@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 308 bytes --]
Hi,
I've added a VDSO patch on my 2.6.32 kernel. When i enabled PREMPT_RT i am
getting the below oops messages.
What is the reason for this ? When googled, it was mentioned in many places
that it is caused by the get_cpu()/put_cpu() preempt disabled region.
Can someone help me to understand this ?
Thanks
[-- Attachment #2: Type: text/html, Size: 508 bytes --]
^ permalink raw reply
* Re: [PATCH v6 08/15] memory-hotplug: Common APIs to support page tables hot-remove
From: Tang Chen @ 2013-01-30 2:16 UTC (permalink / raw)
To: Simon Jeons
Cc: linux-ia64, linux-sh, linux-mm, paulus, hpa, sparclinux, cl,
linux-s390, x86, linux-acpi, isimatu.yasuaki, linfeng, mgorman,
kosaki.motohiro, rientjes, len.brown, wency, cmetcalf, glommer,
wujianguo, yinghai, laijs, linux-kernel, minchan.kim, akpm,
linuxppc-dev
In-Reply-To: <1359464694.1624.18.camel@kernel>
On 01/29/2013 09:04 PM, Simon Jeons wrote:
> Hi Tang,
> On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
>> From: Wen Congyang<wency@cn.fujitsu.com>
>>
>> When memory is removed, the corresponding pagetables should alse be removed.
>> This patch introduces some common APIs to support vmemmap pagetable and x86_64
>> architecture pagetable removing.
>
> Why don't need to build_all_zonelists like online_pages does during
> hot-add path(add_memory)?
Hi Simon,
As you said, build_all_zonelists is done by online_pages. When the
memory device
is hot-added, we cannot use it. we can only use is when we online the
pages on it.
But we can online the pages as different types, kernel or movable (which
belongs to
different zones), and we can online part of the memory, not all of them.
So each time we online some pages, we should check if we need to update
the zone list.
So I think that is why we do build_all_zonelists when online_pages.
(just my opinion)
Thanks. :)
>
>>
>> All pages of virtual mapping in removed memory cannot be freedi if some pages
>> used as PGD/PUD includes not only removed memory but also other memory. So the
>> patch uses the following way to check whether page can be freed or not.
>>
>> 1. When removing memory, the page structs of the revmoved memory are filled
>> with 0FD.
>> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared.
>> In this case, the page used as PT/PMD can be freed.
>>
>> Signed-off-by: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
>> Signed-off-by: Jianguo Wu<wujianguo@huawei.com>
>> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>
>> Signed-off-by: Tang Chen<tangchen@cn.fujitsu.com>
>> ---
>> arch/x86/include/asm/pgtable_types.h | 1 +
>> arch/x86/mm/init_64.c | 299 ++++++++++++++++++++++++++++++++++
>> arch/x86/mm/pageattr.c | 47 +++---
>> include/linux/bootmem.h | 1 +
>> 4 files changed, 326 insertions(+), 22 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
>> index 3c32db8..4b6fd2a 100644
>> --- a/arch/x86/include/asm/pgtable_types.h
>> +++ b/arch/x86/include/asm/pgtable_types.h
>> @@ -352,6 +352,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
>> * as a pte too.
>> */
>> extern pte_t *lookup_address(unsigned long address, unsigned int *level);
>> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
>>
>> #endif /* !__ASSEMBLY__ */
>>
>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
>> index 9ac1723..fe01116 100644
>> --- a/arch/x86/mm/init_64.c
>> +++ b/arch/x86/mm/init_64.c
>> @@ -682,6 +682,305 @@ int arch_add_memory(int nid, u64 start, u64 size)
>> }
>> EXPORT_SYMBOL_GPL(arch_add_memory);
>>
>> +#define PAGE_INUSE 0xFD
>> +
>> +static void __meminit free_pagetable(struct page *page, int order)
>> +{
>> + struct zone *zone;
>> + bool bootmem = false;
>> + unsigned long magic;
>> + unsigned int nr_pages = 1<< order;
>> +
>> + /* bootmem page has reserved flag */
>> + if (PageReserved(page)) {
>> + __ClearPageReserved(page);
>> + bootmem = true;
>> +
>> + magic = (unsigned long)page->lru.next;
>> + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
>> + while (nr_pages--)
>> + put_page_bootmem(page++);
>> + } else
>> + __free_pages_bootmem(page, order);
>> + } else
>> + free_pages((unsigned long)page_address(page), order);
>> +
>> + /*
>> + * SECTION_INFO pages and MIX_SECTION_INFO pages
>> + * are all allocated by bootmem.
>> + */
>> + if (bootmem) {
>> + zone = page_zone(page);
>> + zone_span_writelock(zone);
>> + zone->present_pages += nr_pages;
>> + zone_span_writeunlock(zone);
>> + totalram_pages += nr_pages;
>> + }
>> +}
>> +
>> +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
>> +{
>> + pte_t *pte;
>> + int i;
>> +
>> + for (i = 0; i< PTRS_PER_PTE; i++) {
>> + pte = pte_start + i;
>> + if (pte_val(*pte))
>> + return;
>> + }
>> +
>> + /* free a pte talbe */
>> + free_pagetable(pmd_page(*pmd), 0);
>> + spin_lock(&init_mm.page_table_lock);
>> + pmd_clear(pmd);
>> + spin_unlock(&init_mm.page_table_lock);
>> +}
>> +
>> +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
>> +{
>> + pmd_t *pmd;
>> + int i;
>> +
>> + for (i = 0; i< PTRS_PER_PMD; i++) {
>> + pmd = pmd_start + i;
>> + if (pmd_val(*pmd))
>> + return;
>> + }
>> +
>> + /* free a pmd talbe */
>> + free_pagetable(pud_page(*pud), 0);
>> + spin_lock(&init_mm.page_table_lock);
>> + pud_clear(pud);
>> + spin_unlock(&init_mm.page_table_lock);
>> +}
>> +
>> +/* Return true if pgd is changed, otherwise return false. */
>> +static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
>> +{
>> + pud_t *pud;
>> + int i;
>> +
>> + for (i = 0; i< PTRS_PER_PUD; i++) {
>> + pud = pud_start + i;
>> + if (pud_val(*pud))
>> + return false;
>> + }
>> +
>> + /* free a pud table */
>> + free_pagetable(pgd_page(*pgd), 0);
>> + spin_lock(&init_mm.page_table_lock);
>> + pgd_clear(pgd);
>> + spin_unlock(&init_mm.page_table_lock);
>> +
>> + return true;
>> +}
>> +
>> +static void __meminit
>> +remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
>> + bool direct)
>> +{
>> + unsigned long next, pages = 0;
>> + pte_t *pte;
>> + void *page_addr;
>> + phys_addr_t phys_addr;
>> +
>> + pte = pte_start + pte_index(addr);
>> + for (; addr< end; addr = next, pte++) {
>> + next = (addr + PAGE_SIZE)& PAGE_MASK;
>> + if (next> end)
>> + next = end;
>> +
>> + if (!pte_present(*pte))
>> + continue;
>> +
>> + /*
>> + * We mapped [0,1G) memory as identity mapping when
>> + * initializing, in arch/x86/kernel/head_64.S. These
>> + * pagetables cannot be removed.
>> + */
>> + phys_addr = pte_val(*pte) + (addr& PAGE_MASK);
>> + if (phys_addr< (phys_addr_t)0x40000000)
>> + return;
>> +
>> + if (IS_ALIGNED(addr, PAGE_SIZE)&&
>> + IS_ALIGNED(next, PAGE_SIZE)) {
>> + if (!direct) {
>> + free_pagetable(pte_page(*pte), 0);
>> + pages++;
>> + }
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pte_clear(&init_mm, addr, pte);
>> + spin_unlock(&init_mm.page_table_lock);
>> + } else {
>> + /*
>> + * If we are not removing the whole page, it means
>> + * other ptes in this page are being used and we canot
>> + * remove them. So fill the unused ptes with 0xFD, and
>> + * remove the page when it is wholly filled with 0xFD.
>> + */
>> + memset((void *)addr, PAGE_INUSE, next - addr);
>> + page_addr = page_address(pte_page(*pte));
>> +
>> + if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
>> + free_pagetable(pte_page(*pte), 0);
>> + pages++;
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pte_clear(&init_mm, addr, pte);
>> + spin_unlock(&init_mm.page_table_lock);
>> + }
>> + }
>> + }
>> +
>> + /* Call free_pte_table() in remove_pmd_table(). */
>> + flush_tlb_all();
>> + if (direct)
>> + update_page_count(PG_LEVEL_4K, -pages);
>> +}
>> +
>> +static void __meminit
>> +remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
>> + bool direct)
>> +{
>> + unsigned long pte_phys, next, pages = 0;
>> + pte_t *pte_base;
>> + pmd_t *pmd;
>> +
>> + pmd = pmd_start + pmd_index(addr);
>> + for (; addr< end; addr = next, pmd++) {
>> + next = pmd_addr_end(addr, end);
>> +
>> + if (!pmd_present(*pmd))
>> + continue;
>> +
>> + if (pmd_large(*pmd)) {
>> + if (IS_ALIGNED(addr, PMD_SIZE)&&
>> + IS_ALIGNED(next, PMD_SIZE)) {
>> + if (!direct) {
>> + free_pagetable(pmd_page(*pmd),
>> + get_order(PMD_SIZE));
>> + pages++;
>> + }
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pmd_clear(pmd);
>> + spin_unlock(&init_mm.page_table_lock);
>> + continue;
>> + }
>> +
>> + /*
>> + * We use 2M page, but we need to remove part of them,
>> + * so split 2M page to 4K page.
>> + */
>> + pte_base = (pte_t *)alloc_low_page(&pte_phys);
>> + BUG_ON(!pte_base);
>> + __split_large_page((pte_t *)pmd, addr,
>> + (pte_t *)pte_base);
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
>> + spin_unlock(&init_mm.page_table_lock);
>> +
>> + flush_tlb_all();
>> + }
>> +
>> + pte_base = (pte_t *)map_low_page((pte_t *)pmd_page_vaddr(*pmd));
>> + remove_pte_table(pte_base, addr, next, direct);
>> + free_pte_table(pte_base, pmd);
>> + unmap_low_page(pte_base);
>> + }
>> +
>> + /* Call free_pmd_table() in remove_pud_table(). */
>> + if (direct)
>> + update_page_count(PG_LEVEL_2M, -pages);
>> +}
>> +
>> +static void __meminit
>> +remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
>> + bool direct)
>> +{
>> + unsigned long pmd_phys, next, pages = 0;
>> + pmd_t *pmd_base;
>> + pud_t *pud;
>> +
>> + pud = pud_start + pud_index(addr);
>> + for (; addr< end; addr = next, pud++) {
>> + next = pud_addr_end(addr, end);
>> +
>> + if (!pud_present(*pud))
>> + continue;
>> +
>> + if (pud_large(*pud)) {
>> + if (IS_ALIGNED(addr, PUD_SIZE)&&
>> + IS_ALIGNED(next, PUD_SIZE)) {
>> + if (!direct) {
>> + free_pagetable(pud_page(*pud),
>> + get_order(PUD_SIZE));
>> + pages++;
>> + }
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pud_clear(pud);
>> + spin_unlock(&init_mm.page_table_lock);
>> + continue;
>> + }
>> +
>> + /*
>> + * We use 1G page, but we need to remove part of them,
>> + * so split 1G page to 2M page.
>> + */
>> + pmd_base = (pmd_t *)alloc_low_page(&pmd_phys);
>> + BUG_ON(!pmd_base);
>> + __split_large_page((pte_t *)pud, addr,
>> + (pte_t *)pmd_base);
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pud_populate(&init_mm, pud, __va(pmd_phys));
>> + spin_unlock(&init_mm.page_table_lock);
>> +
>> + flush_tlb_all();
>> + }
>> +
>> + pmd_base = (pmd_t *)map_low_page((pmd_t *)pud_page_vaddr(*pud));
>> + remove_pmd_table(pmd_base, addr, next, direct);
>> + free_pmd_table(pmd_base, pud);
>> + unmap_low_page(pmd_base);
>> + }
>> +
>> + if (direct)
>> + update_page_count(PG_LEVEL_1G, -pages);
>> +}
>> +
>> +/* start and end are both virtual address. */
>> +static void __meminit
>> +remove_pagetable(unsigned long start, unsigned long end, bool direct)
>> +{
>> + unsigned long next;
>> + pgd_t *pgd;
>> + pud_t *pud;
>> + bool pgd_changed = false;
>> +
>> + for (; start< end; start = next) {
>> + pgd = pgd_offset_k(start);
>> + if (!pgd_present(*pgd))
>> + continue;
>> +
>> + next = pgd_addr_end(start, end);
>> +
>> + pud = (pud_t *)map_low_page((pud_t *)pgd_page_vaddr(*pgd));
>> + remove_pud_table(pud, start, next, direct);
>> + if (free_pud_table(pud, pgd))
>> + pgd_changed = true;
>> + unmap_low_page(pud);
>> + }
>> +
>> + if (pgd_changed)
>> + sync_global_pgds(start, end - 1);
>> +
>> + flush_tlb_all();
>> +}
>> +
>> #ifdef CONFIG_MEMORY_HOTREMOVE
>> int __ref arch_remove_memory(u64 start, u64 size)
>> {
>> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
>> index a718e0d..7dcb6f9 100644
>> --- a/arch/x86/mm/pageattr.c
>> +++ b/arch/x86/mm/pageattr.c
>> @@ -501,21 +501,13 @@ out_unlock:
>> return do_split;
>> }
>>
>> -static int split_large_page(pte_t *kpte, unsigned long address)
>> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
>> {
>> unsigned long pfn, pfninc = 1;
>> unsigned int i, level;
>> - pte_t *pbase, *tmp;
>> + pte_t *tmp;
>> pgprot_t ref_prot;
>> - struct page *base;
>> -
>> - if (!debug_pagealloc)
>> - spin_unlock(&cpa_lock);
>> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
>> - if (!debug_pagealloc)
>> - spin_lock(&cpa_lock);
>> - if (!base)
>> - return -ENOMEM;
>> + struct page *base = virt_to_page(pbase);
>>
>> spin_lock(&pgd_lock);
>> /*
>> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
>> * up for us already:
>> */
>> tmp = lookup_address(address,&level);
>> - if (tmp != kpte)
>> - goto out_unlock;
>> + if (tmp != kpte) {
>> + spin_unlock(&pgd_lock);
>> + return 1;
>> + }
>>
>> - pbase = (pte_t *)page_address(base);
>> paravirt_alloc_pte(&init_mm, page_to_pfn(base));
>> ref_prot = pte_pgprot(pte_clrhuge(*kpte));
>> /*
>> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
>> * going on.
>> */
>> __flush_tlb_all();
>> + spin_unlock(&pgd_lock);
>>
>> - base = NULL;
>> + return 0;
>> +}
>>
>> -out_unlock:
>> - /*
>> - * If we dropped out via the lookup_address check under
>> - * pgd_lock then stick the page back into the pool:
>> - */
>> - if (base)
>> +static int split_large_page(pte_t *kpte, unsigned long address)
>> +{
>> + pte_t *pbase;
>> + struct page *base;
>> +
>> + if (!debug_pagealloc)
>> + spin_unlock(&cpa_lock);
>> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
>> + if (!debug_pagealloc)
>> + spin_lock(&cpa_lock);
>> + if (!base)
>> + return -ENOMEM;
>> +
>> + pbase = (pte_t *)page_address(base);
>> + if (__split_large_page(kpte, address, pbase))
>> __free_page(base);
>> - spin_unlock(&pgd_lock);
>>
>> return 0;
>> }
>> diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
>> index 3f778c2..190ff06 100644
>> --- a/include/linux/bootmem.h
>> +++ b/include/linux/bootmem.h
>> @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
>> unsigned long size);
>> extern void free_bootmem(unsigned long physaddr, unsigned long size);
>> extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
>> +extern void __free_pages_bootmem(struct page *page, unsigned int order);
>>
>> /*
>> * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply
* Re: [PATCH v6 08/15] memory-hotplug: Common APIs to support page tables hot-remove
From: Simon Jeons @ 2013-01-30 2:13 UTC (permalink / raw)
To: Jianguo Wu
Cc: linux-ia64, linux-sh, Tang Chen, linux-mm, paulus, hpa,
sparclinux, cl, linux-s390, x86, linux-acpi, isimatu.yasuaki,
linfeng, mgorman, kosaki.motohiro, rientjes, len.brown, wency,
cmetcalf, glommer, yinghai, laijs, linux-kernel, minchan.kim,
akpm, linuxppc-dev
In-Reply-To: <51087D09.4090205@huawei.com>
On Wed, 2013-01-30 at 09:53 +0800, Jianguo Wu wrote:
> On 2013/1/29 21:02, Simon Jeons wrote:
>
> > Hi Tang,
> > On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
> >> From: Wen Congyang <wency@cn.fujitsu.com>
> >>
> >> When memory is removed, the corresponding pagetables should alse be removed.
> >> This patch introduces some common APIs to support vmemmap pagetable and x86_64
> >> architecture pagetable removing.
> >>
> >
> > When page table of hot-add memory is created?
>
>
> Hi Simon,
>
> For x86_64, page table of hot-add memory is created by:
> add_memory->arch_add_memory->init_memory_mapping->kernel_physical_mapping_init
Yup, thanks. :)
>
> >
> >> All pages of virtual mapping in removed memory cannot be freedi if some pages
> >> used as PGD/PUD includes not only removed memory but also other memory. So the
> >> patch uses the following way to check whether page can be freed or not.
> >>
> >> 1. When removing memory, the page structs of the revmoved memory are filled
> >> with 0FD.
> >> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared.
> >> In this case, the page used as PT/PMD can be freed.
> >>
> >> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> >> Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> >> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> >> ---
> >> arch/x86/include/asm/pgtable_types.h | 1 +
> >> arch/x86/mm/init_64.c | 299 ++++++++++++++++++++++++++++++++++
> >> arch/x86/mm/pageattr.c | 47 +++---
> >> include/linux/bootmem.h | 1 +
> >> 4 files changed, 326 insertions(+), 22 deletions(-)
> >>
> >> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
> >> index 3c32db8..4b6fd2a 100644
> >> --- a/arch/x86/include/asm/pgtable_types.h
> >> +++ b/arch/x86/include/asm/pgtable_types.h
> >> @@ -352,6 +352,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
> >> * as a pte too.
> >> */
> >> extern pte_t *lookup_address(unsigned long address, unsigned int *level);
> >> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
> >>
> >> #endif /* !__ASSEMBLY__ */
> >>
> >> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> >> index 9ac1723..fe01116 100644
> >> --- a/arch/x86/mm/init_64.c
> >> +++ b/arch/x86/mm/init_64.c
> >> @@ -682,6 +682,305 @@ int arch_add_memory(int nid, u64 start, u64 size)
> >> }
> >> EXPORT_SYMBOL_GPL(arch_add_memory);
> >>
> >> +#define PAGE_INUSE 0xFD
> >> +
> >> +static void __meminit free_pagetable(struct page *page, int order)
> >> +{
> >> + struct zone *zone;
> >> + bool bootmem = false;
> >> + unsigned long magic;
> >> + unsigned int nr_pages = 1 << order;
> >> +
> >> + /* bootmem page has reserved flag */
> >> + if (PageReserved(page)) {
> >> + __ClearPageReserved(page);
> >> + bootmem = true;
> >> +
> >> + magic = (unsigned long)page->lru.next;
> >> + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
> >> + while (nr_pages--)
> >> + put_page_bootmem(page++);
> >> + } else
> >> + __free_pages_bootmem(page, order);
> >> + } else
> >> + free_pages((unsigned long)page_address(page), order);
> >> +
> >> + /*
> >> + * SECTION_INFO pages and MIX_SECTION_INFO pages
> >> + * are all allocated by bootmem.
> >> + */
> >> + if (bootmem) {
> >> + zone = page_zone(page);
> >> + zone_span_writelock(zone);
> >> + zone->present_pages += nr_pages;
> >> + zone_span_writeunlock(zone);
> >> + totalram_pages += nr_pages;
> >> + }
> >> +}
> >> +
> >> +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
> >> +{
> >> + pte_t *pte;
> >> + int i;
> >> +
> >> + for (i = 0; i < PTRS_PER_PTE; i++) {
> >> + pte = pte_start + i;
> >> + if (pte_val(*pte))
> >> + return;
> >> + }
> >> +
> >> + /* free a pte talbe */
> >> + free_pagetable(pmd_page(*pmd), 0);
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pmd_clear(pmd);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +}
> >> +
> >> +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
> >> +{
> >> + pmd_t *pmd;
> >> + int i;
> >> +
> >> + for (i = 0; i < PTRS_PER_PMD; i++) {
> >> + pmd = pmd_start + i;
> >> + if (pmd_val(*pmd))
> >> + return;
> >> + }
> >> +
> >> + /* free a pmd talbe */
> >> + free_pagetable(pud_page(*pud), 0);
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pud_clear(pud);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +}
> >> +
> >> +/* Return true if pgd is changed, otherwise return false. */
> >> +static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
> >> +{
> >> + pud_t *pud;
> >> + int i;
> >> +
> >> + for (i = 0; i < PTRS_PER_PUD; i++) {
> >> + pud = pud_start + i;
> >> + if (pud_val(*pud))
> >> + return false;
> >> + }
> >> +
> >> + /* free a pud table */
> >> + free_pagetable(pgd_page(*pgd), 0);
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pgd_clear(pgd);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +
> >> + return true;
> >> +}
> >> +
> >> +static void __meminit
> >> +remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
> >> + bool direct)
> >> +{
> >> + unsigned long next, pages = 0;
> >> + pte_t *pte;
> >> + void *page_addr;
> >> + phys_addr_t phys_addr;
> >> +
> >> + pte = pte_start + pte_index(addr);
> >> + for (; addr < end; addr = next, pte++) {
> >> + next = (addr + PAGE_SIZE) & PAGE_MASK;
> >> + if (next > end)
> >> + next = end;
> >> +
> >> + if (!pte_present(*pte))
> >> + continue;
> >> +
> >> + /*
> >> + * We mapped [0,1G) memory as identity mapping when
> >> + * initializing, in arch/x86/kernel/head_64.S. These
> >> + * pagetables cannot be removed.
> >> + */
> >> + phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
> >> + if (phys_addr < (phys_addr_t)0x40000000)
> >> + return;
> >> +
> >> + if (IS_ALIGNED(addr, PAGE_SIZE) &&
> >> + IS_ALIGNED(next, PAGE_SIZE)) {
> >> + if (!direct) {
> >> + free_pagetable(pte_page(*pte), 0);
> >> + pages++;
> >> + }
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pte_clear(&init_mm, addr, pte);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + } else {
> >> + /*
> >> + * If we are not removing the whole page, it means
> >> + * other ptes in this page are being used and we canot
> >> + * remove them. So fill the unused ptes with 0xFD, and
> >> + * remove the page when it is wholly filled with 0xFD.
> >> + */
> >> + memset((void *)addr, PAGE_INUSE, next - addr);
> >> + page_addr = page_address(pte_page(*pte));
> >> +
> >> + if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
> >> + free_pagetable(pte_page(*pte), 0);
> >> + pages++;
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pte_clear(&init_mm, addr, pte);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + }
> >> + }
> >> + }
> >> +
> >> + /* Call free_pte_table() in remove_pmd_table(). */
> >> + flush_tlb_all();
> >> + if (direct)
> >> + update_page_count(PG_LEVEL_4K, -pages);
> >> +}
> >> +
> >> +static void __meminit
> >> +remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
> >> + bool direct)
> >> +{
> >> + unsigned long pte_phys, next, pages = 0;
> >> + pte_t *pte_base;
> >> + pmd_t *pmd;
> >> +
> >> + pmd = pmd_start + pmd_index(addr);
> >> + for (; addr < end; addr = next, pmd++) {
> >> + next = pmd_addr_end(addr, end);
> >> +
> >> + if (!pmd_present(*pmd))
> >> + continue;
> >> +
> >> + if (pmd_large(*pmd)) {
> >> + if (IS_ALIGNED(addr, PMD_SIZE) &&
> >> + IS_ALIGNED(next, PMD_SIZE)) {
> >> + if (!direct) {
> >> + free_pagetable(pmd_page(*pmd),
> >> + get_order(PMD_SIZE));
> >> + pages++;
> >> + }
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pmd_clear(pmd);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + continue;
> >> + }
> >> +
> >> + /*
> >> + * We use 2M page, but we need to remove part of them,
> >> + * so split 2M page to 4K page.
> >> + */
> >> + pte_base = (pte_t *)alloc_low_page(&pte_phys);
> >> + BUG_ON(!pte_base);
> >> + __split_large_page((pte_t *)pmd, addr,
> >> + (pte_t *)pte_base);
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +
> >> + flush_tlb_all();
> >> + }
> >> +
> >> + pte_base = (pte_t *)map_low_page((pte_t *)pmd_page_vaddr(*pmd));
> >> + remove_pte_table(pte_base, addr, next, direct);
> >> + free_pte_table(pte_base, pmd);
> >> + unmap_low_page(pte_base);
> >> + }
> >> +
> >> + /* Call free_pmd_table() in remove_pud_table(). */
> >> + if (direct)
> >> + update_page_count(PG_LEVEL_2M, -pages);
> >> +}
> >> +
> >> +static void __meminit
> >> +remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
> >> + bool direct)
> >> +{
> >> + unsigned long pmd_phys, next, pages = 0;
> >> + pmd_t *pmd_base;
> >> + pud_t *pud;
> >> +
> >> + pud = pud_start + pud_index(addr);
> >> + for (; addr < end; addr = next, pud++) {
> >> + next = pud_addr_end(addr, end);
> >> +
> >> + if (!pud_present(*pud))
> >> + continue;
> >> +
> >> + if (pud_large(*pud)) {
> >> + if (IS_ALIGNED(addr, PUD_SIZE) &&
> >> + IS_ALIGNED(next, PUD_SIZE)) {
> >> + if (!direct) {
> >> + free_pagetable(pud_page(*pud),
> >> + get_order(PUD_SIZE));
> >> + pages++;
> >> + }
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pud_clear(pud);
> >> + spin_unlock(&init_mm.page_table_lock);
> >> + continue;
> >> + }
> >> +
> >> + /*
> >> + * We use 1G page, but we need to remove part of them,
> >> + * so split 1G page to 2M page.
> >> + */
> >> + pmd_base = (pmd_t *)alloc_low_page(&pmd_phys);
> >> + BUG_ON(!pmd_base);
> >> + __split_large_page((pte_t *)pud, addr,
> >> + (pte_t *)pmd_base);
> >> +
> >> + spin_lock(&init_mm.page_table_lock);
> >> + pud_populate(&init_mm, pud, __va(pmd_phys));
> >> + spin_unlock(&init_mm.page_table_lock);
> >> +
> >> + flush_tlb_all();
> >> + }
> >> +
> >> + pmd_base = (pmd_t *)map_low_page((pmd_t *)pud_page_vaddr(*pud));
> >> + remove_pmd_table(pmd_base, addr, next, direct);
> >> + free_pmd_table(pmd_base, pud);
> >> + unmap_low_page(pmd_base);
> >> + }
> >> +
> >> + if (direct)
> >> + update_page_count(PG_LEVEL_1G, -pages);
> >> +}
> >> +
> >> +/* start and end are both virtual address. */
> >> +static void __meminit
> >> +remove_pagetable(unsigned long start, unsigned long end, bool direct)
> >> +{
> >> + unsigned long next;
> >> + pgd_t *pgd;
> >> + pud_t *pud;
> >> + bool pgd_changed = false;
> >> +
> >> + for (; start < end; start = next) {
> >> + pgd = pgd_offset_k(start);
> >> + if (!pgd_present(*pgd))
> >> + continue;
> >> +
> >> + next = pgd_addr_end(start, end);
> >> +
> >> + pud = (pud_t *)map_low_page((pud_t *)pgd_page_vaddr(*pgd));
> >> + remove_pud_table(pud, start, next, direct);
> >> + if (free_pud_table(pud, pgd))
> >> + pgd_changed = true;
> >> + unmap_low_page(pud);
> >> + }
> >> +
> >> + if (pgd_changed)
> >> + sync_global_pgds(start, end - 1);
> >> +
> >> + flush_tlb_all();
> >> +}
> >> +
> >> #ifdef CONFIG_MEMORY_HOTREMOVE
> >> int __ref arch_remove_memory(u64 start, u64 size)
> >> {
> >> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
> >> index a718e0d..7dcb6f9 100644
> >> --- a/arch/x86/mm/pageattr.c
> >> +++ b/arch/x86/mm/pageattr.c
> >> @@ -501,21 +501,13 @@ out_unlock:
> >> return do_split;
> >> }
> >>
> >> -static int split_large_page(pte_t *kpte, unsigned long address)
> >> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
> >> {
> >> unsigned long pfn, pfninc = 1;
> >> unsigned int i, level;
> >> - pte_t *pbase, *tmp;
> >> + pte_t *tmp;
> >> pgprot_t ref_prot;
> >> - struct page *base;
> >> -
> >> - if (!debug_pagealloc)
> >> - spin_unlock(&cpa_lock);
> >> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
> >> - if (!debug_pagealloc)
> >> - spin_lock(&cpa_lock);
> >> - if (!base)
> >> - return -ENOMEM;
> >> + struct page *base = virt_to_page(pbase);
> >>
> >> spin_lock(&pgd_lock);
> >> /*
> >> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
> >> * up for us already:
> >> */
> >> tmp = lookup_address(address, &level);
> >> - if (tmp != kpte)
> >> - goto out_unlock;
> >> + if (tmp != kpte) {
> >> + spin_unlock(&pgd_lock);
> >> + return 1;
> >> + }
> >>
> >> - pbase = (pte_t *)page_address(base);
> >> paravirt_alloc_pte(&init_mm, page_to_pfn(base));
> >> ref_prot = pte_pgprot(pte_clrhuge(*kpte));
> >> /*
> >> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
> >> * going on.
> >> */
> >> __flush_tlb_all();
> >> + spin_unlock(&pgd_lock);
> >>
> >> - base = NULL;
> >> + return 0;
> >> +}
> >>
> >> -out_unlock:
> >> - /*
> >> - * If we dropped out via the lookup_address check under
> >> - * pgd_lock then stick the page back into the pool:
> >> - */
> >> - if (base)
> >> +static int split_large_page(pte_t *kpte, unsigned long address)
> >> +{
> >> + pte_t *pbase;
> >> + struct page *base;
> >> +
> >> + if (!debug_pagealloc)
> >> + spin_unlock(&cpa_lock);
> >> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
> >> + if (!debug_pagealloc)
> >> + spin_lock(&cpa_lock);
> >> + if (!base)
> >> + return -ENOMEM;
> >> +
> >> + pbase = (pte_t *)page_address(base);
> >> + if (__split_large_page(kpte, address, pbase))
> >> __free_page(base);
> >> - spin_unlock(&pgd_lock);
> >>
> >> return 0;
> >> }
> >> diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
> >> index 3f778c2..190ff06 100644
> >> --- a/include/linux/bootmem.h
> >> +++ b/include/linux/bootmem.h
> >> @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
> >> unsigned long size);
> >> extern void free_bootmem(unsigned long physaddr, unsigned long size);
> >> extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
> >> +extern void __free_pages_bootmem(struct page *page, unsigned int order);
> >>
> >> /*
> >> * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
> >
> >
> >
> > .
> >
>
>
>
^ permalink raw reply
* Re: [PATCH v6 08/15] memory-hotplug: Common APIs to support page tables hot-remove
From: Jianguo Wu @ 2013-01-30 1:53 UTC (permalink / raw)
To: Simon Jeons
Cc: linux-ia64, linux-sh, Tang Chen, linux-mm, paulus, hpa,
sparclinux, cl, linux-s390, x86, linux-acpi, isimatu.yasuaki,
linfeng, mgorman, kosaki.motohiro, rientjes, len.brown, wency,
cmetcalf, glommer, yinghai, laijs, linux-kernel, minchan.kim,
akpm, linuxppc-dev
In-Reply-To: <1359464544.1624.16.camel@kernel>
On 2013/1/29 21:02, Simon Jeons wrote:
> Hi Tang,
> On Wed, 2013-01-09 at 17:32 +0800, Tang Chen wrote:
>> From: Wen Congyang <wency@cn.fujitsu.com>
>>
>> When memory is removed, the corresponding pagetables should alse be removed.
>> This patch introduces some common APIs to support vmemmap pagetable and x86_64
>> architecture pagetable removing.
>>
>
> When page table of hot-add memory is created?
Hi Simon,
For x86_64, page table of hot-add memory is created by:
add_memory->arch_add_memory->init_memory_mapping->kernel_physical_mapping_init
>
>> All pages of virtual mapping in removed memory cannot be freedi if some pages
>> used as PGD/PUD includes not only removed memory but also other memory. So the
>> patch uses the following way to check whether page can be freed or not.
>>
>> 1. When removing memory, the page structs of the revmoved memory are filled
>> with 0FD.
>> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared.
>> In this case, the page used as PT/PMD can be freed.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>> Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
>> ---
>> arch/x86/include/asm/pgtable_types.h | 1 +
>> arch/x86/mm/init_64.c | 299 ++++++++++++++++++++++++++++++++++
>> arch/x86/mm/pageattr.c | 47 +++---
>> include/linux/bootmem.h | 1 +
>> 4 files changed, 326 insertions(+), 22 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
>> index 3c32db8..4b6fd2a 100644
>> --- a/arch/x86/include/asm/pgtable_types.h
>> +++ b/arch/x86/include/asm/pgtable_types.h
>> @@ -352,6 +352,7 @@ static inline void update_page_count(int level, unsigned long pages) { }
>> * as a pte too.
>> */
>> extern pte_t *lookup_address(unsigned long address, unsigned int *level);
>> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
>>
>> #endif /* !__ASSEMBLY__ */
>>
>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
>> index 9ac1723..fe01116 100644
>> --- a/arch/x86/mm/init_64.c
>> +++ b/arch/x86/mm/init_64.c
>> @@ -682,6 +682,305 @@ int arch_add_memory(int nid, u64 start, u64 size)
>> }
>> EXPORT_SYMBOL_GPL(arch_add_memory);
>>
>> +#define PAGE_INUSE 0xFD
>> +
>> +static void __meminit free_pagetable(struct page *page, int order)
>> +{
>> + struct zone *zone;
>> + bool bootmem = false;
>> + unsigned long magic;
>> + unsigned int nr_pages = 1 << order;
>> +
>> + /* bootmem page has reserved flag */
>> + if (PageReserved(page)) {
>> + __ClearPageReserved(page);
>> + bootmem = true;
>> +
>> + magic = (unsigned long)page->lru.next;
>> + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
>> + while (nr_pages--)
>> + put_page_bootmem(page++);
>> + } else
>> + __free_pages_bootmem(page, order);
>> + } else
>> + free_pages((unsigned long)page_address(page), order);
>> +
>> + /*
>> + * SECTION_INFO pages and MIX_SECTION_INFO pages
>> + * are all allocated by bootmem.
>> + */
>> + if (bootmem) {
>> + zone = page_zone(page);
>> + zone_span_writelock(zone);
>> + zone->present_pages += nr_pages;
>> + zone_span_writeunlock(zone);
>> + totalram_pages += nr_pages;
>> + }
>> +}
>> +
>> +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
>> +{
>> + pte_t *pte;
>> + int i;
>> +
>> + for (i = 0; i < PTRS_PER_PTE; i++) {
>> + pte = pte_start + i;
>> + if (pte_val(*pte))
>> + return;
>> + }
>> +
>> + /* free a pte talbe */
>> + free_pagetable(pmd_page(*pmd), 0);
>> + spin_lock(&init_mm.page_table_lock);
>> + pmd_clear(pmd);
>> + spin_unlock(&init_mm.page_table_lock);
>> +}
>> +
>> +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
>> +{
>> + pmd_t *pmd;
>> + int i;
>> +
>> + for (i = 0; i < PTRS_PER_PMD; i++) {
>> + pmd = pmd_start + i;
>> + if (pmd_val(*pmd))
>> + return;
>> + }
>> +
>> + /* free a pmd talbe */
>> + free_pagetable(pud_page(*pud), 0);
>> + spin_lock(&init_mm.page_table_lock);
>> + pud_clear(pud);
>> + spin_unlock(&init_mm.page_table_lock);
>> +}
>> +
>> +/* Return true if pgd is changed, otherwise return false. */
>> +static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
>> +{
>> + pud_t *pud;
>> + int i;
>> +
>> + for (i = 0; i < PTRS_PER_PUD; i++) {
>> + pud = pud_start + i;
>> + if (pud_val(*pud))
>> + return false;
>> + }
>> +
>> + /* free a pud table */
>> + free_pagetable(pgd_page(*pgd), 0);
>> + spin_lock(&init_mm.page_table_lock);
>> + pgd_clear(pgd);
>> + spin_unlock(&init_mm.page_table_lock);
>> +
>> + return true;
>> +}
>> +
>> +static void __meminit
>> +remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
>> + bool direct)
>> +{
>> + unsigned long next, pages = 0;
>> + pte_t *pte;
>> + void *page_addr;
>> + phys_addr_t phys_addr;
>> +
>> + pte = pte_start + pte_index(addr);
>> + for (; addr < end; addr = next, pte++) {
>> + next = (addr + PAGE_SIZE) & PAGE_MASK;
>> + if (next > end)
>> + next = end;
>> +
>> + if (!pte_present(*pte))
>> + continue;
>> +
>> + /*
>> + * We mapped [0,1G) memory as identity mapping when
>> + * initializing, in arch/x86/kernel/head_64.S. These
>> + * pagetables cannot be removed.
>> + */
>> + phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
>> + if (phys_addr < (phys_addr_t)0x40000000)
>> + return;
>> +
>> + if (IS_ALIGNED(addr, PAGE_SIZE) &&
>> + IS_ALIGNED(next, PAGE_SIZE)) {
>> + if (!direct) {
>> + free_pagetable(pte_page(*pte), 0);
>> + pages++;
>> + }
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pte_clear(&init_mm, addr, pte);
>> + spin_unlock(&init_mm.page_table_lock);
>> + } else {
>> + /*
>> + * If we are not removing the whole page, it means
>> + * other ptes in this page are being used and we canot
>> + * remove them. So fill the unused ptes with 0xFD, and
>> + * remove the page when it is wholly filled with 0xFD.
>> + */
>> + memset((void *)addr, PAGE_INUSE, next - addr);
>> + page_addr = page_address(pte_page(*pte));
>> +
>> + if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
>> + free_pagetable(pte_page(*pte), 0);
>> + pages++;
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pte_clear(&init_mm, addr, pte);
>> + spin_unlock(&init_mm.page_table_lock);
>> + }
>> + }
>> + }
>> +
>> + /* Call free_pte_table() in remove_pmd_table(). */
>> + flush_tlb_all();
>> + if (direct)
>> + update_page_count(PG_LEVEL_4K, -pages);
>> +}
>> +
>> +static void __meminit
>> +remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
>> + bool direct)
>> +{
>> + unsigned long pte_phys, next, pages = 0;
>> + pte_t *pte_base;
>> + pmd_t *pmd;
>> +
>> + pmd = pmd_start + pmd_index(addr);
>> + for (; addr < end; addr = next, pmd++) {
>> + next = pmd_addr_end(addr, end);
>> +
>> + if (!pmd_present(*pmd))
>> + continue;
>> +
>> + if (pmd_large(*pmd)) {
>> + if (IS_ALIGNED(addr, PMD_SIZE) &&
>> + IS_ALIGNED(next, PMD_SIZE)) {
>> + if (!direct) {
>> + free_pagetable(pmd_page(*pmd),
>> + get_order(PMD_SIZE));
>> + pages++;
>> + }
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pmd_clear(pmd);
>> + spin_unlock(&init_mm.page_table_lock);
>> + continue;
>> + }
>> +
>> + /*
>> + * We use 2M page, but we need to remove part of them,
>> + * so split 2M page to 4K page.
>> + */
>> + pte_base = (pte_t *)alloc_low_page(&pte_phys);
>> + BUG_ON(!pte_base);
>> + __split_large_page((pte_t *)pmd, addr,
>> + (pte_t *)pte_base);
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
>> + spin_unlock(&init_mm.page_table_lock);
>> +
>> + flush_tlb_all();
>> + }
>> +
>> + pte_base = (pte_t *)map_low_page((pte_t *)pmd_page_vaddr(*pmd));
>> + remove_pte_table(pte_base, addr, next, direct);
>> + free_pte_table(pte_base, pmd);
>> + unmap_low_page(pte_base);
>> + }
>> +
>> + /* Call free_pmd_table() in remove_pud_table(). */
>> + if (direct)
>> + update_page_count(PG_LEVEL_2M, -pages);
>> +}
>> +
>> +static void __meminit
>> +remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
>> + bool direct)
>> +{
>> + unsigned long pmd_phys, next, pages = 0;
>> + pmd_t *pmd_base;
>> + pud_t *pud;
>> +
>> + pud = pud_start + pud_index(addr);
>> + for (; addr < end; addr = next, pud++) {
>> + next = pud_addr_end(addr, end);
>> +
>> + if (!pud_present(*pud))
>> + continue;
>> +
>> + if (pud_large(*pud)) {
>> + if (IS_ALIGNED(addr, PUD_SIZE) &&
>> + IS_ALIGNED(next, PUD_SIZE)) {
>> + if (!direct) {
>> + free_pagetable(pud_page(*pud),
>> + get_order(PUD_SIZE));
>> + pages++;
>> + }
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pud_clear(pud);
>> + spin_unlock(&init_mm.page_table_lock);
>> + continue;
>> + }
>> +
>> + /*
>> + * We use 1G page, but we need to remove part of them,
>> + * so split 1G page to 2M page.
>> + */
>> + pmd_base = (pmd_t *)alloc_low_page(&pmd_phys);
>> + BUG_ON(!pmd_base);
>> + __split_large_page((pte_t *)pud, addr,
>> + (pte_t *)pmd_base);
>> +
>> + spin_lock(&init_mm.page_table_lock);
>> + pud_populate(&init_mm, pud, __va(pmd_phys));
>> + spin_unlock(&init_mm.page_table_lock);
>> +
>> + flush_tlb_all();
>> + }
>> +
>> + pmd_base = (pmd_t *)map_low_page((pmd_t *)pud_page_vaddr(*pud));
>> + remove_pmd_table(pmd_base, addr, next, direct);
>> + free_pmd_table(pmd_base, pud);
>> + unmap_low_page(pmd_base);
>> + }
>> +
>> + if (direct)
>> + update_page_count(PG_LEVEL_1G, -pages);
>> +}
>> +
>> +/* start and end are both virtual address. */
>> +static void __meminit
>> +remove_pagetable(unsigned long start, unsigned long end, bool direct)
>> +{
>> + unsigned long next;
>> + pgd_t *pgd;
>> + pud_t *pud;
>> + bool pgd_changed = false;
>> +
>> + for (; start < end; start = next) {
>> + pgd = pgd_offset_k(start);
>> + if (!pgd_present(*pgd))
>> + continue;
>> +
>> + next = pgd_addr_end(start, end);
>> +
>> + pud = (pud_t *)map_low_page((pud_t *)pgd_page_vaddr(*pgd));
>> + remove_pud_table(pud, start, next, direct);
>> + if (free_pud_table(pud, pgd))
>> + pgd_changed = true;
>> + unmap_low_page(pud);
>> + }
>> +
>> + if (pgd_changed)
>> + sync_global_pgds(start, end - 1);
>> +
>> + flush_tlb_all();
>> +}
>> +
>> #ifdef CONFIG_MEMORY_HOTREMOVE
>> int __ref arch_remove_memory(u64 start, u64 size)
>> {
>> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
>> index a718e0d..7dcb6f9 100644
>> --- a/arch/x86/mm/pageattr.c
>> +++ b/arch/x86/mm/pageattr.c
>> @@ -501,21 +501,13 @@ out_unlock:
>> return do_split;
>> }
>>
>> -static int split_large_page(pte_t *kpte, unsigned long address)
>> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
>> {
>> unsigned long pfn, pfninc = 1;
>> unsigned int i, level;
>> - pte_t *pbase, *tmp;
>> + pte_t *tmp;
>> pgprot_t ref_prot;
>> - struct page *base;
>> -
>> - if (!debug_pagealloc)
>> - spin_unlock(&cpa_lock);
>> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
>> - if (!debug_pagealloc)
>> - spin_lock(&cpa_lock);
>> - if (!base)
>> - return -ENOMEM;
>> + struct page *base = virt_to_page(pbase);
>>
>> spin_lock(&pgd_lock);
>> /*
>> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
>> * up for us already:
>> */
>> tmp = lookup_address(address, &level);
>> - if (tmp != kpte)
>> - goto out_unlock;
>> + if (tmp != kpte) {
>> + spin_unlock(&pgd_lock);
>> + return 1;
>> + }
>>
>> - pbase = (pte_t *)page_address(base);
>> paravirt_alloc_pte(&init_mm, page_to_pfn(base));
>> ref_prot = pte_pgprot(pte_clrhuge(*kpte));
>> /*
>> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, unsigned long address)
>> * going on.
>> */
>> __flush_tlb_all();
>> + spin_unlock(&pgd_lock);
>>
>> - base = NULL;
>> + return 0;
>> +}
>>
>> -out_unlock:
>> - /*
>> - * If we dropped out via the lookup_address check under
>> - * pgd_lock then stick the page back into the pool:
>> - */
>> - if (base)
>> +static int split_large_page(pte_t *kpte, unsigned long address)
>> +{
>> + pte_t *pbase;
>> + struct page *base;
>> +
>> + if (!debug_pagealloc)
>> + spin_unlock(&cpa_lock);
>> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
>> + if (!debug_pagealloc)
>> + spin_lock(&cpa_lock);
>> + if (!base)
>> + return -ENOMEM;
>> +
>> + pbase = (pte_t *)page_address(base);
>> + if (__split_large_page(kpte, address, pbase))
>> __free_page(base);
>> - spin_unlock(&pgd_lock);
>>
>> return 0;
>> }
>> diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
>> index 3f778c2..190ff06 100644
>> --- a/include/linux/bootmem.h
>> +++ b/include/linux/bootmem.h
>> @@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
>> unsigned long size);
>> extern void free_bootmem(unsigned long physaddr, unsigned long size);
>> extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
>> +extern void __free_pages_bootmem(struct page *page, unsigned int order);
>>
>> /*
>> * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
>
>
>
> .
>
^ permalink raw reply
* Re: [PATCH 4/5] net: mvmdio: allow Device Tree and platform device to coexist
From: Florian Fainelli @ 2013-01-29 20:41 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Thomas Petazzoni, Andrew Lunn, Russell King, Jason Cooper,
linux-doc, devicetree-discuss, linux-kernel, Rob Herring,
Greg Kroah-Hartman, Paul Mackerras, Lennert Buytenhek,
Rob Landley, netdev, linuxppc-dev, davem, linux-arm-kernel
In-Reply-To: <20130129175912.GE25646@obsidianresearch.com>
Le mardi 29 janvier 2013 18:59:12, Jason Gunthorpe a =E9crit :
> On Tue, Jan 29, 2013 at 04:24:07PM +0100, Florian Fainelli wrote:
> > - dev->err_interrupt =3D irq_of_parse_and_map(pdev->dev.of_node, 0);
> > + if (pdev->dev.of_node) {
> > + dev->regs =3D of_iomap(pdev->dev.of_node, 0);
> > + if (!dev->regs) {
> > + dev_err(&pdev->dev, "No SMI register address given in=20
DT\n");
> > + ret =3D -ENODEV;
> > + goto out_free;
> > + }
> > +
> > + dev->err_interrupt =3D irq_of_parse_and_map(pdev->dev.of_node, 0);
> > + } else {
> > + r =3D platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +
> > + dev->regs =3D ioremap(r->start, resource_size(r));
> > + if (!dev->regs) {
> > + dev_err(&pdev->dev, "No SMI register address given\n");
> > + ret =3D -ENODEV;
> > + goto out_free;
> > + }
> > +
> > + dev->err_interrupt =3D platform_get_irq(pdev, 0);
> > + }
>=20
> Why do you have these different paths for OF and platform? AFAIK these
> days when a OF device is automatically converted into a platform
> device all the struct resources are created too, so you can't you just
> use platform_get_resource and devm_request_and_ioremap for both flows?
>=20
> Ditto for the interrupt - platform_get_irq should work in both cases?
There was no particular reason and I updated the patchset to do that precis=
ely=20
in version 2.
=2D-=20
=46lorian
^ permalink raw reply
* Re: [PATCH 5/5] mv643xx_eth: convert to use the Marvell Orion MDIO driver
From: Florian Fainelli @ 2013-01-29 20:41 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Thomas Petazzoni, Andrew Lunn, Russell King, Jason Cooper,
linux-doc, devicetree-discuss, linux-kernel, Rob Herring,
Greg Kroah-Hartman, Paul Mackerras, Lennert Buytenhek,
Rob Landley, netdev, linuxppc-dev, davem, linux-arm-kernel
In-Reply-To: <20130129181306.GF25646@obsidianresearch.com>
Le mardi 29 janvier 2013 19:13:06, Jason Gunthorpe a =E9crit :
> On Tue, Jan 29, 2013 at 04:24:08PM +0100, Florian Fainelli wrote:
> > This patch converts the Marvell MV643XX ethernet driver to use the
> > Marvell Orion MDIO driver. As a result, PowerPC and ARM platforms
> > registering the Marvell MV643XX ethernet driver are also updated to
> > register a Marvell Orion MDIO driver. This driver voluntarily overlaps
> > with the Marvell Ethernet shared registers because it will use a subset
> > of this shared register (shared_base + 0x4 - shared_base + 0x84). The
> > Ethernet driver is also updated to look up for a PHY device using the
> > Orion MDIO bus driver.
>=20
> Can you finish off this job by making the mv643xx_eth driver accept
> the standard phy-handle OF property instead of using a phy address?
I can certainly do that, at the same time we need to continue supporting th=
e=20
"old" platform device style registration without breaking them (PowerPC in=
=20
particular, and the hopefully yet to be converted orion5x). So the phy_scan=
()=20
as I modified it will probably still be there.
>=20
> Ie the end result should be something like:
>=20
> smi0: mdio@72000 {
> device_type =3D "mdio";
> compatible =3D "marvell,orion-mdio";
> reg =3D <0x72004 0x4>;
>=20
> #address-cells =3D <1>;
> #size-cells =3D <0>;
> PHY1: ethernet-phy@1 {
> reg =3D <1>;
> device_type =3D "ethernet-phy";
> phy-id =3D <0x01410e90>;
> };
> };
>=20
> egiga0 {
> device_type =3D "network";
> compatible =3D "marvell,mv643xx-eth";
> reg =3D <0x72000 0x4000>;
> port_number =3D <0>;
> phy-handle =3D <&PHY1>;
> interrupts =3D <11>;
> local-mac-address =3D [000000000002]; /* Filled =
by
> boot loader */ };
>=20
> Regards,
> Jason
=2D-=20
=46lorian
^ permalink raw reply
* Re: [PATCH 2/2] pseries/iommu: remove DDW on kexec
From: Nishanth Aravamudan @ 2013-01-29 20:33 UTC (permalink / raw)
To: Michael Ellerman; +Cc: miltonm, paulus, anton, nfont, linuxppc-dev
In-Reply-To: <1359457108.26096.7.camel@concordia>
Hi Michael,
On 29.01.2013 [21:58:28 +1100], Michael Ellerman wrote:
> On Mon, 2013-01-28 at 18:03 -0800, Nishanth Aravamudan wrote:
> > pseries/iommu: remove DDW on kexec
> > ...
> >
> > I believe the simplest, easiest-to-maintain fix is to just change our
> > initcall to, rather than detecting and updating the new kernel's DDW
> > knowledge, just remove all DDW configurations. When the drivers
> > re-initialize, we will set everything back up as it was before.
>
> I don't know this code at all, but this sounds like it will also work
> for kdump, right? ie. when the original kernel has crashed the 2nd
> kernel will tear the DDW down and set it back up.
Yes, my actual test-case (and what was reported as broken) was kdump.
>From my relatively vague (but now growing) understanding of that
process, kdump does use kexec under the covers to switch to the crash
kernel, and so does get the same benefit from this change.
Another datapoint, though, is that it might make sense to recommend (and
I'm working on figuring this out for the distros, etc) to use
disable_ddw anyways for the kdump kernel command-line, as DDW isn't
'free' and it's unclear if performance is a huge concern for the crash
kernel (sort of varies with where your storage is, and how much you need
to dump, which for kdump generally doesn't seem like that much?).
Thanks,
Nish
^ permalink raw reply
* Re: [PATCH 4/5] net: mvmdio: allow Device Tree and platform device to coexist
From: Jason Gunthorpe @ 2013-01-29 17:59 UTC (permalink / raw)
To: Florian Fainelli
Cc: Thomas Petazzoni, Andrew Lunn, Russell King, Jason Cooper,
linux-doc, devicetree-discuss, linux-kernel, Rob Herring,
Greg Kroah-Hartman, Paul Mackerras, Lennert Buytenhek,
Rob Landley, netdev, linuxppc-dev, davem, linux-arm-kernel
In-Reply-To: <1359473048-26551-5-git-send-email-florian@openwrt.org>
On Tue, Jan 29, 2013 at 04:24:07PM +0100, Florian Fainelli wrote:
> - dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
> + if (pdev->dev.of_node) {
> + dev->regs = of_iomap(pdev->dev.of_node, 0);
> + if (!dev->regs) {
> + dev_err(&pdev->dev, "No SMI register address given in DT\n");
> + ret = -ENODEV;
> + goto out_free;
> + }
> +
> + dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
> + } else {
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> + dev->regs = ioremap(r->start, resource_size(r));
> + if (!dev->regs) {
> + dev_err(&pdev->dev, "No SMI register address given\n");
> + ret = -ENODEV;
> + goto out_free;
> + }
> +
> + dev->err_interrupt = platform_get_irq(pdev, 0);
> + }
Why do you have these different paths for OF and platform? AFAIK these
days when a OF device is automatically converted into a platform
device all the struct resources are created too, so you can't you just
use platform_get_resource and devm_request_and_ioremap for both flows?
Ditto for the interrupt - platform_get_irq should work in both cases?
Jason
^ permalink raw reply
* Re: [PATCH 5/5] mv643xx_eth: convert to use the Marvell Orion MDIO driver
From: Jason Gunthorpe @ 2013-01-29 18:13 UTC (permalink / raw)
To: Florian Fainelli
Cc: Thomas Petazzoni, Andrew Lunn, Russell King, Jason Cooper,
linux-doc, devicetree-discuss, linux-kernel, Rob Herring,
Greg Kroah-Hartman, Paul Mackerras, Lennert Buytenhek,
Rob Landley, netdev, linuxppc-dev, davem, linux-arm-kernel
In-Reply-To: <1359473048-26551-6-git-send-email-florian@openwrt.org>
On Tue, Jan 29, 2013 at 04:24:08PM +0100, Florian Fainelli wrote:
> This patch converts the Marvell MV643XX ethernet driver to use the
> Marvell Orion MDIO driver. As a result, PowerPC and ARM platforms
> registering the Marvell MV643XX ethernet driver are also updated to
> register a Marvell Orion MDIO driver. This driver voluntarily overlaps
> with the Marvell Ethernet shared registers because it will use a subset
> of this shared register (shared_base + 0x4 - shared_base + 0x84). The
> Ethernet driver is also updated to look up for a PHY device using the
> Orion MDIO bus driver.
Can you finish off this job by making the mv643xx_eth driver accept
the standard phy-handle OF property instead of using a phy address?
Ie the end result should be something like:
smi0: mdio@72000 {
device_type = "mdio";
compatible = "marvell,orion-mdio";
reg = <0x72004 0x4>;
#address-cells = <1>;
#size-cells = <0>;
PHY1: ethernet-phy@1 {
reg = <1>;
device_type = "ethernet-phy";
phy-id = <0x01410e90>;
};
};
egiga0 {
device_type = "network";
compatible = "marvell,mv643xx-eth";
reg = <0x72000 0x4000>;
port_number = <0>;
phy-handle = <&PHY1>;
interrupts = <11>;
local-mac-address = [000000000002]; /* Filled by boot loader */
};
Regards,
Jason
^ permalink raw reply
* Re: [PATCH 5/5] mv643xx_eth: convert to use the Marvell Orion MDIO driver
From: Thomas Petazzoni @ 2013-01-29 16:46 UTC (permalink / raw)
To: Florian Fainelli
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <5107F88C.8030002@openwrt.org>
Dear Florian Fainelli,
On Tue, 29 Jan 2013 17:27:56 +0100, Florian Fainelli wrote:
> It looks like I introduced two redundant mvmdio instances as ge01
> refers to the ge00 smi bus (the same applies to ge11 and ge10).
> Thanks for spotting this.
Ok, good.
> If you take a closer look at mv643xx_eth you will see that the
> "shared" driver still handles the mconf bus window configuration,
> which is not abstracted yet.
Indeed, I've seen that. But I don't understand why it's done in the
mv643xx_eth_shared_probe(). The mbus window configuration registers are
per-network interface, so this call to mv643xx_eth_conf_mbus_windows()
could presumably be done in mv643xx_eth_probe().
At least in mvneta, we have the same registers, and we do their
initialization in the driver normal (and only) ->probe() routine.
> Besides that, I would rather do it step by step.
Yes, agreed. But I think it would be good to have followed patches that
progressively get rid of the shared driver thing, as it will help in
bringing a proper DT binding in the mv643xx_eth driver. But it
certainly doesn't need to be part of this specific patch.
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* Re: [PATCH 5/5] mv643xx_eth: convert to use the Marvell Orion MDIO driver
From: Florian Fainelli @ 2013-01-29 16:27 UTC (permalink / raw)
To: Thomas Petazzoni
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <20130129170131.7964a110@skate>
On 01/29/2013 05:01 PM, Thomas Petazzoni wrote:
> Dear Florian Fainelli,
>
> On Tue, 29 Jan 2013 16:24:08 +0100, Florian Fainelli wrote:
>> This patch converts the Marvell MV643XX ethernet driver to use the
>> Marvell Orion MDIO driver. As a result, PowerPC and ARM platforms
>> registering the Marvell MV643XX ethernet driver are also updated to
>> register a Marvell Orion MDIO driver. This driver voluntarily overlaps
>> with the Marvell Ethernet shared registers because it will use a subset
>> of this shared register (shared_base + 0x4 - shared_base + 0x84). The
>> Ethernet driver is also updated to look up for a PHY device using the
>> Orion MDIO bus driver.
>>
>> Signed-off-by: Florian Fainelli <florian@openwrt.org>
>> ---
>> arch/arm/plat-orion/common.c | 84 +++++++++++--
> In this file, there was one "MV643XX_ETH_SHARED_NAME" platform_device
> registered for each network interface. Why? If the driver is shared,
> isn't the whole idea to register it only once?
It looks like I introduced two redundant mvmdio instances as ge01 refers
to the ge00 smi bus (the same applies to ge11 and ge10). Thanks for
spotting this.
>
> In any case, one of the idea of separating the mvmdio driver from the
> mvneta driver in the first place is that there should be only one
> instance of the mvmdio device, even if there are multiple network
> interfaces. The reason is that from a HW point of the view, the MDIO
> unit is shared between the network interfaces. If you look at
> armada-370-xp.dtsi, there is only one mvmdio device registered, and two
> network interfaces (using the mvneta driver) that are registered (and
> actually up to four network interfaces can exist, they are added by
> some other .dtsi files depending on the specific SoC).
>
> So I don't think there should be one instance of the mvmdio per network
> interface.
>
> Also, I am wondering what's left in this MV643XX_ETH_SHARED_NAME driver
> once the MDIO stuff has been pulled out in a separate driver? I think
> the whole point of this work should be to get rid of this
> MV643XX_ETH_SHARED_NAME driver, no?
If you take a closer look at mv643xx_eth you will see that the "shared"
driver still handles the mconf bus window configuration, which is not
abstracted yet. Besides that, I would rather do it step by step.
--
Florian
^ permalink raw reply
* Re: [PATCH 5/5] mv643xx_eth: convert to use the Marvell Orion MDIO driver
From: Thomas Petazzoni @ 2013-01-29 16:01 UTC (permalink / raw)
To: Florian Fainelli
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <1359473048-26551-6-git-send-email-florian@openwrt.org>
Dear Florian Fainelli,
On Tue, 29 Jan 2013 16:24:08 +0100, Florian Fainelli wrote:
> This patch converts the Marvell MV643XX ethernet driver to use the
> Marvell Orion MDIO driver. As a result, PowerPC and ARM platforms
> registering the Marvell MV643XX ethernet driver are also updated to
> register a Marvell Orion MDIO driver. This driver voluntarily overlaps
> with the Marvell Ethernet shared registers because it will use a subset
> of this shared register (shared_base + 0x4 - shared_base + 0x84). The
> Ethernet driver is also updated to look up for a PHY device using the
> Orion MDIO bus driver.
>
> Signed-off-by: Florian Fainelli <florian@openwrt.org>
> ---
> arch/arm/plat-orion/common.c | 84 +++++++++++--
In this file, there was one "MV643XX_ETH_SHARED_NAME" platform_device
registered for each network interface. Why? If the driver is shared,
isn't the whole idea to register it only once?
In any case, one of the idea of separating the mvmdio driver from the
mvneta driver in the first place is that there should be only one
instance of the mvmdio device, even if there are multiple network
interfaces. The reason is that from a HW point of the view, the MDIO
unit is shared between the network interfaces. If you look at
armada-370-xp.dtsi, there is only one mvmdio device registered, and two
network interfaces (using the mvneta driver) that are registered (and
actually up to four network interfaces can exist, they are added by
some other .dtsi files depending on the specific SoC).
So I don't think there should be one instance of the mvmdio per network
interface.
Also, I am wondering what's left in this MV643XX_ETH_SHARED_NAME driver
once the MDIO stuff has been pulled out in a separate driver? I think
the whole point of this work should be to get rid of this
MV643XX_ETH_SHARED_NAME driver, no?
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* Re: [PATCH 4/5] net: mvmdio: allow Device Tree and platform device to coexist
From: Thomas Petazzoni @ 2013-01-29 15:48 UTC (permalink / raw)
To: Florian Fainelli
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <1359473048-26551-5-git-send-email-florian@openwrt.org>
Dear Florian Fainelli,
On Tue, 29 Jan 2013 16:24:07 +0100, Florian Fainelli wrote:
> This patch changes the Marvell MDIO driver to be registered by using
> both Device Tree and platform device methods. The driver voluntarily
> does not use devm_ioremap() to share the same error path for Device Tree
> and non-Device Tree cases.
Not sure why you think devm_ioremap() can't be used here. Maybe I'm
missing something, but could you explain? If you use devm_ioremap(),
then basically you don't need to do anything in the error path
regarding to the I/O mapping... since it's the whole purpose of the
devm_*() stuff to automagically undo things in the error case, and in
the ->remove() code.
> - dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
> + if (pdev->dev.of_node) {
> + dev->regs = of_iomap(pdev->dev.of_node, 0);
> + if (!dev->regs) {
> + dev_err(&pdev->dev, "No SMI register address given in DT\n");
> + ret = -ENODEV;
> + goto out_free;
> + }
> +
> + dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
> + } else {
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> + dev->regs = ioremap(r->start, resource_size(r));
> + if (!dev->regs) {
> + dev_err(&pdev->dev, "No SMI register address given\n");
> + ret = -ENODEV;
> + goto out_free;
> + }
> +
> + dev->err_interrupt = platform_get_irq(pdev, 0);
> + }
I think you can do a devm_ioremap() and a platform_get_irq() in both
cases here, and therefore keep the code common between the DT case and
the !DT case.
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* Re: [PATCH 2/5] net: mvmdio: rename base register cookie from smireg to regs
From: Thomas Petazzoni @ 2013-01-29 15:34 UTC (permalink / raw)
To: Florian Fainelli
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <1359473048-26551-3-git-send-email-florian@openwrt.org>
Dear Florian Fainelli,
On Tue, 29 Jan 2013 16:24:05 +0100, Florian Fainelli wrote:
> This patch renames the base register cookie in the mvmdio drive from
> "smireg" to "regs" since a subsequent patch is going to use an ioremap()
> cookie whose size is larger than a single register of 4 bytes. No
> functionnal code change introduced.
>
> Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* Re: [PATCH 1/5] net: mvmdio: unmap base register address at driver removal
From: Thomas Petazzoni @ 2013-01-29 15:32 UTC (permalink / raw)
To: Florian Fainelli
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <1359473048-26551-2-git-send-email-florian@openwrt.org>
Dear Florian Fainelli,
On Tue, 29 Jan 2013 16:24:04 +0100, Florian Fainelli wrote:
> Fix the driver remove callback to unmap the base register address and
> not leak this mapping after the driver has been removed.
>
> Signed-off-by: Florian Fainelli <florian@openwrt.org>
What about using devm_request_and_ioremap() instead, in order to get
automatic unmap on error and in the ->remove() path?
But maybe it won't work because this memory range is claimed both by
the MDIO driver and the Ethernet driver itself. In that case, you could
use devm_ioremap().
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* Re: [PATCH 3/5] net: mvmdio: enhance driver to support SMI error/done interrupts
From: Thomas Petazzoni @ 2013-01-29 15:39 UTC (permalink / raw)
To: Florian Fainelli
Cc: Andrew Lunn, Russell King, Jason Cooper, linux-doc,
devicetree-discuss, linux-kernel, Rob Herring, netdev,
Paul Mackerras, linux-arm-kernel, Rob Landley, Greg Kroah-Hartman,
linuxppc-dev, davem, Lennert Buytenhek
In-Reply-To: <1359473048-26551-4-git-send-email-florian@openwrt.org>
Dear Florian Fainelli,
On Tue, 29 Jan 2013 16:24:06 +0100, Florian Fainelli wrote:
> #define MVMDIO_SMI_DATA_SHIFT 0
> #define MVMDIO_SMI_PHY_ADDR_SHIFT 16
> @@ -36,12 +40,28 @@
> #define MVMDIO_SMI_WRITE_OPERATION 0
> #define MVMDIO_SMI_READ_VALID BIT(27)
> #define MVMDIO_SMI_BUSY BIT(28)
> +#define MVMDIO_ERR_INT_CAUSE 0x007C
> +#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
> +#define MVMDIO_ERR_INT_MASK 0x0080
>
> struct orion_mdio_dev {
> struct mutex lock;
> void __iomem *regs;
> + /*
> + * If we have access to the error interrupt pin (which is
> + * somewhat misnamed as it not only reflects internal errors
> + * but also reflects SMI completion), use that to wait for
> + * SMI access completion instead of polling the SMI busy bit.
> + */
> + int err_interrupt;
> + wait_queue_head_t smi_busy_wait;
> };
>
> +static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
> +{
> + return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
> +}
> +
> /* Wait for the SMI unit to be ready for another operation
> */
> static int orion_mdio_wait_ready(struct mii_bus *bus)
> @@ -50,19 +70,30 @@ static int orion_mdio_wait_ready(struct mii_bus *bus)
> int count;
> u32 val;
>
> - count = 0;
> - while (1) {
> - val = readl(dev->regs);
> - if (!(val & MVMDIO_SMI_BUSY))
> - break;
> -
> - if (count > 100) {
> - dev_err(bus->parent, "Timeout: SMI busy for too long\n");
> - return -ETIMEDOUT;
> + if (dev->err_interrupt == NO_IRQ) {
> + count = 0;
> + while (1) {
> + val = readl(dev->regs);
> + if (!(val & MVMDIO_SMI_BUSY))
> + break;
What about using your new orion_mdio_smi_is_done() function here?
> +
> + if (count > 100) {
> + dev_err(bus->parent,
> + "Timeout: SMI busy for too long\n");
> + return -ETIMEDOUT;
> + }
> +
> + udelay(10);
> + count++;
> }
> + }
>
> - udelay(10);
> - count++;
> + if (!orion_mdio_smi_is_done(dev)) {
Maybe it should be in an else if block so that the waitqueue case is
only considered if there is an IRQ registered? Of course practically
speaking, it's OK because if there is no IRQ, we'll wait in the polling
loop above, and either exit from the function on timeout, or continue
on success. But it still would make the code a little bit clearer, I'd
say.
> static int orion_mdio_probe(struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> @@ -181,6 +227,19 @@ static int orion_mdio_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> + dev->err_interrupt = NO_IRQ;
Not needed, you already do dev->err_interrupt = something() below.
> + init_waitqueue_head(&dev->smi_busy_wait);
> +
> + dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
> + if (dev->err_interrupt != NO_IRQ) {
> + ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
> + orion_mdio_err_irq,
> + IRQF_SHARED, pdev->name, dev);
> + if (!ret)
> + writel(MVMDIO_ERR_INT_SMI_DONE,
> + dev->regs + MVMDIO_ERR_INT_MASK);
> + }
> +
> mutex_init(&dev->lock);
>
> ret = of_mdiobus_register(bus, np);
> @@ -202,6 +261,8 @@ static int orion_mdio_remove(struct platform_device *pdev)
> struct mii_bus *bus = platform_get_drvdata(pdev);
> struct orion_mdio_dev *dev = bus->priv;
>
> + writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
> + free_irq(dev->err_interrupt, dev);
free_irq() not needed since the IRQ handler is registered with
devm_request_irq().
> mdiobus_unregister(bus);
> kfree(bus->irq);
> mdiobus_free(bus);
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
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