* Re: [PATCH v2 6/6] mm/memory_hotplug: Pass nid instead of zone to __remove_pages()
2019-08-26 10:10 ` [PATCH v2 6/6] mm/memory_hotplug: Pass nid instead of zone to __remove_pages() David Hildenbrand
@ 2019-08-27 10:49 ` Robin Murphy
0 siblings, 0 replies; 2+ messages in thread
From: Robin Murphy @ 2019-08-27 10:49 UTC (permalink / raw)
To: David Hildenbrand, linux-kernel
Cc: Mark Rutland, linux-s390, Rich Felker, linux-ia64, Tom Lendacky,
Peter Zijlstra, Dave Hansen, Heiko Carstens, Wei Yang, linux-mm,
Michal Hocko, Paul Mackerras, H. Peter Anvin, Will Deacon,
Dan Williams, Halil Pasic, Yu Zhao, Yoshinori Sato,
Jason Gunthorpe, linux-sh, x86, Matthew Wilcox (Oracle),
Mike Rapoport, Jun Yao, Christian Borntraeger, Ingo Molnar,
linux-arm-kernel, Catalin Marinas, Ira Weiny, Fenghua Yu,
Pavel Tatashin, Vasily Gorbik, Anshuman Khandual, Masahiro Yamada,
linuxppc-dev, Borislav Petkov, Andy Lutomirski, Thomas Gleixner,
Gerald Schaefer, Oscar Salvador, Tony Luck, Steve Capper,
Greg Kroah-Hartman, Aneesh Kumar K.V, Qian Cai, Andrew Morton,
Logan Gunthorpe
On 26/08/2019 11:10, David Hildenbrand wrote:
> The zone parameter is no longer in use. Replace it with the nid, which
> we can now use the nid to limit the number of zones we have to process
> (vie for_each_zone_nid()). The function signature of __remove_pages() now
> looks much more similar to the one of __add_pages().
FWIW I recall this being trivially easy to hit when first playing with
hotremove development for arm64 - since we only have 3 zones, the page
flags poison would cause page_zone() to dereference past the end of
node_zones[] and go all kinds of wrong. This looks like a definite
improvement in API terms.
For arm64,
Acked-by: Robin Murphy <robin.murphy@arm.com>
Cheers,
Robin.
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Cc: Rich Felker <dalias@libc.org>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: x86@kernel.org
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Steve Capper <steve.capper@arm.com>
> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Yu Zhao <yuzhao@google.com>
> Cc: Jun Yao <yaojun8558363@gmail.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> Cc: Christophe Leroy <christophe.leroy@c-s.fr>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
> Cc: Halil Pasic <pasic@linux.ibm.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Wei Yang <richard.weiyang@gmail.com>
> Cc: Qian Cai <cai@lca.pw>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Logan Gunthorpe <logang@deltatee.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-ia64@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-s390@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> arch/arm64/mm/mmu.c | 4 +---
> arch/ia64/mm/init.c | 4 +---
> arch/powerpc/mm/mem.c | 3 +--
> arch/s390/mm/init.c | 4 +---
> arch/sh/mm/init.c | 4 +---
> arch/x86/mm/init_32.c | 4 +---
> arch/x86/mm/init_64.c | 4 +---
> include/linux/memory_hotplug.h | 2 +-
> mm/memory_hotplug.c | 17 +++++++++--------
> mm/memremap.c | 3 +--
> 10 files changed, 18 insertions(+), 31 deletions(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index e67bab4d613e..9a2d388314f3 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1080,7 +1080,6 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> /*
> * FIXME: Cleanup page tables (also in arch_add_memory() in case
> @@ -1089,7 +1088,6 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> * unplug. ARCH_ENABLE_MEMORY_HOTREMOVE must not be
> * unlocked yet.
> */
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
> }
> #endif
> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index bf9df2625bc8..ae6a3e718aa0 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -689,9 +689,7 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
> }
> #endif
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index 9191a66b3bc5..af21e13529ce 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -130,10 +130,9 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
> int ret;
>
> - __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
>
> /* Remove htab bolted mappings for this section of memory */
> start = (unsigned long)__va(start);
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 20340a03ad90..2a7373ed6ded 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -296,10 +296,8 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
> vmem_remove_mapping(start, size);
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
> index dfdbaa50946e..32441b59297d 100644
> --- a/arch/sh/mm/init.c
> +++ b/arch/sh/mm/init.c
> @@ -434,9 +434,7 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = PFN_DOWN(start);
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
> index 4068abb9427f..2760e4bfbc56 100644
> --- a/arch/x86/mm/init_32.c
> +++ b/arch/x86/mm/init_32.c
> @@ -865,10 +865,8 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
> }
> #endif
>
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index a6b5c653727b..99d92297f1cf 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -1212,10 +1212,8 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
> - struct zone *zone = page_zone(page);
>
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(nid, start_pfn, nr_pages, altmap);
> kernel_physical_mapping_remove(start, start + size);
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index f46ea71b4ffd..c5b38e7dc8aa 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -125,7 +125,7 @@ static inline bool movable_node_is_enabled(void)
>
> extern void arch_remove_memory(int nid, u64 start, u64 size,
> struct vmem_altmap *altmap);
> -extern void __remove_pages(struct zone *zone, unsigned long start_pfn,
> +extern void __remove_pages(int nid, unsigned long start_pfn,
> unsigned long nr_pages, struct vmem_altmap *altmap);
>
> /* reasonably generic interface to expand the physical pages */
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index e88c96cf9d77..49ca3364eb70 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -514,7 +514,7 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn,
> pgdat_resize_unlock(zone->zone_pgdat, &flags);
> }
>
> -static void __remove_section(unsigned long pfn, unsigned long nr_pages,
> +static void __remove_section(int nid, unsigned long pfn, unsigned long nr_pages,
> unsigned long map_offset,
> struct vmem_altmap *altmap)
> {
> @@ -525,14 +525,14 @@ static void __remove_section(unsigned long pfn, unsigned long nr_pages,
> return;
>
> /* TODO: move zone handling out of memory removal path */
> - for_each_zone(zone)
> + for_each_zone_nid(zone, nid)
> __remove_zone(zone, pfn, nr_pages);
> sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap);
> }
>
> /**
> * __remove_pages() - remove sections of pages from a zone
> - * @zone: zone from which pages need to be removed
> + * @nid: the nid all pages were added to
> * @pfn: starting pageframe (must be aligned to start of a section)
> * @nr_pages: number of pages to remove (must be multiple of section size)
> * @altmap: alternative device page map or %NULL if default memmap is used
> @@ -542,12 +542,13 @@ static void __remove_section(unsigned long pfn, unsigned long nr_pages,
> * sure that pages are marked reserved and zones are adjust properly by
> * calling offline_pages().
> */
> -void __remove_pages(struct zone *zone, unsigned long pfn,
> - unsigned long nr_pages, struct vmem_altmap *altmap)
> +void __remove_pages(int nid, unsigned long pfn, unsigned long nr_pages,
> + struct vmem_altmap *altmap)
> {
> const unsigned long end_pfn = pfn + nr_pages;
> unsigned long cur_nr_pages;
> unsigned long map_offset = 0;
> + struct zone *zone;
>
> if (check_pfn_span(pfn, nr_pages, "remove"))
> return;
> @@ -555,7 +556,7 @@ void __remove_pages(struct zone *zone, unsigned long pfn,
> map_offset = vmem_altmap_offset(altmap);
>
> /* TODO: move zone handling out of memory removal path */
> - for_each_zone(zone)
> + for_each_zone_nid(zone, nid)
> if (zone_intersects(zone, pfn, nr_pages))
> clear_zone_contiguous(zone);
>
> @@ -563,12 +564,12 @@ void __remove_pages(struct zone *zone, unsigned long pfn,
> cond_resched();
> /* Select all remaining pages up to the next section boundary */
> cur_nr_pages = min(end_pfn - pfn, -(pfn | PAGE_SECTION_MASK));
> - __remove_section(pfn, cur_nr_pages, map_offset, altmap);
> + __remove_section(nid, pfn, cur_nr_pages, map_offset, altmap);
> map_offset = 0;
> }
>
> /* TODO: move zone handling out of memory removal path */
> - for_each_zone(zone)
> + for_each_zone_nid(zone, nid)
> set_zone_contiguous(zone);
> }
>
> diff --git a/mm/memremap.c b/mm/memremap.c
> index 8a394552b5bd..292ef4c6b447 100644
> --- a/mm/memremap.c
> +++ b/mm/memremap.c
> @@ -138,8 +138,7 @@ static void devm_memremap_pages_release(void *data)
> mem_hotplug_begin();
> if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
> pfn = PHYS_PFN(res->start);
> - __remove_pages(page_zone(pfn_to_page(pfn)), pfn,
> - PHYS_PFN(resource_size(res)), NULL);
> + __remove_pages(nid, pfn, PHYS_PFN(resource_size(res)), NULL);
> } else {
> arch_remove_memory(nid, res->start, resource_size(res),
> pgmap_altmap(pgmap));
>
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