Re: [PATCH v7] hugetlbfs: Extend the definition of hugepages parameter to support node allocation

Zhenguo Yao
2021-10-04T15:06:35Z

Hi Mike:

Thanks for your review. I notice that this patch has already been in
linux-next. Do I need to submit another version of this patch or
provide a new patch to fix the problems you pointed out?

Mike Kravetz <mike.kravetz@oracle.com> 于2021年10月2日周六 上午6:33写道：
>
> On 9/27/21 3:41 AM, Zhenguo Yao wrote:
> > We can specify the number of hugepages to allocate at boot. But the
> > hugepages is balanced in all nodes at present. In some scenarios,
> > we only need hugepages in one node. For example: DPDK needs hugepages
> > which are in the same node as NIC. if DPDK needs four hugepages of 1G
> > size in node1 and system has 16 numa nodes. We must reserve 64 hugepages
> > in kernel cmdline. But, only four hugepages are used. The others should
> > be free after boot. If the system memory is low(for example: 64G), it will
> > be an impossible task. So, Extending hugepages parameter to support
> > specifying hugepages at a specific node.
> > For example add following parameter:
> >
> > hugepagesz=1G hugepages=0:1,1:3
> >
> > It will allocate 1 hugepage in node0 and 3 hugepages in node1.
> >
> > Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
>
> Thanks for your continued efforts! And, thank you Mike R. for your
> input.
>
> Just a few very minor comments below. Everything else looks good.
> With suggested updates,
>
> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
>
> > ---
> > v6->v7 changes:
> > - replace nodes_weight(node_states[N_MEMORY] with nr_online_nodes.
> > v5->v6 changes:
> > - Remove v5 codes: using return value to disable node specific alloc.
> > - Add node_specific_alloc_support weak function to disable node
> > specific alloc when arch can't support it.
> > - Remove useless variable addr in alloc_bootmem_huge_page.
> > - Add powerpc version of node_specific_alloc_support when
> > CONFIG_PPC_BOOK3S_64 is defined.
> > v4->v5 changes:
> > - remove BUG_ON in __alloc_bootmem_huge_page.
> > - add nid parameter in __alloc_bootmem_huge_page to support
> > called in both specific node alloc and normal alloc.
> > - do normal alloc if architecture can't support node specific alloc.
> > - return -1 in powerpc version of alloc_bootmem_huge_page when
> > nid is not NUMA_NO_NODE.
> > v3->v4 changes:
> > - fix wrong behavior for parameter:
> > hugepages=0:1,1:3 default_hugepagesz=1G
> > - make the change of documentation more reasonable.
> > v2->v3 changes:
> > - Skip gigantic hugepages allocation if hugetlb_cma is enabled.
> > - Fix wrong behavior for parameter:
> > hugepagesz=2M hugepages=2 hugepages=5.
> > - Update hugetlbpage.rst.
> > - Fix side effects which v2 brings in.
> > - add cond_resched in hugetlb_hstate_alloc_pages_onenode.
> > v1->v2 changes:
> > - add checking for max node to avoid array out of bounds.
> > - fix wrong max_huge_pages after failed allocation.
> > - fix wrong behavior when parsing parameter: hugepages=0:1,2,3:4.
> > - return 0 when parsing invalid parameter in hugepages_setup
> > ---
> > .../admin-guide/kernel-parameters.txt | 8 +-
> > Documentation/admin-guide/mm/hugetlbpage.rst | 12 +-
> > arch/powerpc/mm/hugetlbpage.c | 9 +-
> > include/linux/hugetlb.h | 6 +-
> > mm/hugetlb.c | 153 +++++++++++++++---
> > 5 files changed, 157 insertions(+), 31 deletions(-)
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index 91ba391f9b32..9b3d8791586d 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -1599,9 +1599,11 @@
> > the number of pages of hugepagesz to be allocated.
> > If this is the first HugeTLB parameter on the command
> > line, it specifies the number of pages to allocate for
> > - the default huge page size. See also
> > - Documentation/admin-guide/mm/hugetlbpage.rst.
> > - Format: <integer>
> > + the default huge page size. If using node format, the
> > + number of pages to allocate per-node can be specified.
> > + See also Documentation/admin-guide/mm/hugetlbpage.rst.
> > + Format: <integer> or (node format)
> > + <node>:<integer>[,<node>:<integer>]
> >
> > hugepagesz=
> > [HW] The size of the HugeTLB pages. This is used in
> > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst
> > index 8abaeb144e44..d70828c07658 100644
> > --- a/Documentation/admin-guide/mm/hugetlbpage.rst
> > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst
> > @@ -128,7 +128,9 @@ hugepages
> > implicitly specifies the number of huge pages of default size to
> > allocate. If the number of huge pages of default size is implicitly
> > specified, it can not be overwritten by a hugepagesz,hugepages
> > - parameter pair for the default size.
> > + parameter pair for the default size. This parameter also has a
> > + node format. The node format specifies the number of huge pages
> > + to allocate on specific nodes.
> >
> > For example, on an architecture with 2M default huge page size::
> >
> > @@ -138,6 +140,14 @@ hugepages
> > indicating that the hugepages=512 parameter is ignored. If a hugepages
> > parameter is preceded by an invalid hugepagesz parameter, it will
> > be ignored.
> > +
> > + Node format example::
> > +
> > + hugepagesz=2M hugepages=0:1,1:2
> > +
> > + It will allocate 1 2M hugepage on node0 and 2 2M hugepages on node1.
> > + If the node number is invalid, the parameter will be ignored.
> > +
> > default_hugepagesz
> > Specify the default huge page size. This parameter can
> > only be specified once on the command line. default_hugepagesz can
> > diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> > index 9a75ba078e1b..dd40ce6e7565 100644
> > --- a/arch/powerpc/mm/hugetlbpage.c
> > +++ b/arch/powerpc/mm/hugetlbpage.c
> > @@ -229,17 +229,22 @@ static int __init pseries_alloc_bootmem_huge_page(struct hstate *hstate)
> > m->hstate = hstate;
> > return 1;
> > }
> > +
> > +bool __init node_specific_alloc_support(void)
> > +{
> > + return false;
> > +}
> > #endif
> >
> >
> > -int __init alloc_bootmem_huge_page(struct hstate *h)
> > +int __init alloc_bootmem_huge_page(struct hstate *h, int nid)
> > {
> >
> > #ifdef CONFIG_PPC_BOOK3S_64
> > if (firmware_has_feature(FW_FEATURE_LPAR) && !radix_enabled())
> > return pseries_alloc_bootmem_huge_page(h);
> > #endif
> > - return __alloc_bootmem_huge_page(h);
> > + return __alloc_bootmem_huge_page(h, nid);
> > }
> >
> > #ifndef CONFIG_PPC_BOOK3S_64
> > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> > index 1faebe1cd0ed..3504e407567c 100644
> > --- a/include/linux/hugetlb.h
> > +++ b/include/linux/hugetlb.h
> > @@ -605,6 +605,7 @@ struct hstate {
> > unsigned long nr_overcommit_huge_pages;
> > struct list_head hugepage_activelist;
> > struct list_head hugepage_freelists[MAX_NUMNODES];
> > + unsigned int max_huge_pages_node[MAX_NUMNODES];
> > unsigned int nr_huge_pages_node[MAX_NUMNODES];
> > unsigned int free_huge_pages_node[MAX_NUMNODES];
> > unsigned int surplus_huge_pages_node[MAX_NUMNODES];
> > @@ -637,8 +638,9 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
> > unsigned long address, struct page *page);
> >
> > /* arch callback */
> > -int __init __alloc_bootmem_huge_page(struct hstate *h);
> > -int __init alloc_bootmem_huge_page(struct hstate *h);
> > +int __init __alloc_bootmem_huge_page(struct hstate *h, int nid);
> > +int __init alloc_bootmem_huge_page(struct hstate *h, int nid);
> > +bool __init node_specific_alloc_support(void);
>
> Agree with Mike R. that hugetlb should be in the name.
>
> >
> > void __init hugetlb_add_hstate(unsigned order);
> > bool __init arch_hugetlb_valid_size(unsigned long size);
> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> > index 95dc7b83381f..ca00676a1bdd 100644
> > --- a/mm/hugetlb.c
> > +++ b/mm/hugetlb.c
> > @@ -66,6 +66,7 @@ static struct hstate * __initdata parsed_hstate;
> > static unsigned long __initdata default_hstate_max_huge_pages;
> > static bool __initdata parsed_valid_hugepagesz = true;
> > static bool __initdata parsed_default_hugepagesz;
> > +static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata;
> >
> > /*
> > * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
> > @@ -2868,33 +2869,41 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
> > return ERR_PTR(-ENOSPC);
> > }
> >
> > -int alloc_bootmem_huge_page(struct hstate *h)
> > +int alloc_bootmem_huge_page(struct hstate *h, int nid)
> > __attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
> > -int __alloc_bootmem_huge_page(struct hstate *h)
> > +int __alloc_bootmem_huge_page(struct hstate *h, int nid)
> > {
> > struct huge_bootmem_page *m;
> > int nr_nodes, node;
> >
> > + if (nid >= nr_online_nodes)
> > + return 0;
> > + /* do node specific alloc */
> > + if (nid != NUMA_NO_NODE) {
> > + m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h),
> > + 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
> > + if (m)
> > + goto found;
> > + else
> > + return 0;
> > + }
> > + /* do all node balanced alloc */
>
> I'm sure you saw Smatch does not like this comment. Perhaps,
> /* allocate from next node when distributing huge pages */
>
> > for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
> > - void *addr;
> > -
> > - addr = memblock_alloc_try_nid_raw(
> > + m = memblock_alloc_try_nid_raw(
> > huge_page_size(h), huge_page_size(h),
> > 0, MEMBLOCK_ALLOC_ACCESSIBLE, node);
> > - if (addr) {
> > - /*
> > - * Use the beginning of the huge page to store the
> > - * huge_bootmem_page struct (until gather_bootmem
> > - * puts them into the mem_map).
> > - */
> > - m = addr;
> > + /*
> > + * Use the beginning of the huge page to store the
> > + * huge_bootmem_page struct (until gather_bootmem
> > + * puts them into the mem_map).
> > + */
> > + if (m)
> > goto found;
> > - }
> > + else
> > + return 0;
> > }
> > - return 0;
> >
> > found:
> > - BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
> > /* Put them into a private list first because mem_map is not up yet */
> > INIT_LIST_HEAD(&m->list);
> > list_add(&m->list, &huge_boot_pages);
> > @@ -2934,12 +2943,61 @@ static void __init gather_bootmem_prealloc(void)
> > cond_resched();
> > }
> > }
> > +static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
> > +{
> > + unsigned long i;
> > + char buf[32];
> > +
> > + for (i = 0; i < h->max_huge_pages_node[nid]; ++i) {
> > + if (hstate_is_gigantic(h)) {
> > + if (!alloc_bootmem_huge_page(h, nid))
> > + break;
> > + } else {
> > + struct page *page;
> > + gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
> > +
> > + page = alloc_fresh_huge_page(h, gfp_mask, nid,
> > + &node_states[N_MEMORY], NULL);
> > + if (!page)
> > + break;
> > + put_page(page); /* free it into the hugepage allocator */
> > + }
> > + cond_resched();
> > + }
> > + if (i == h->max_huge_pages_node[nid])
> > + return;
> > +
> > + string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
> > + pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n",
> > + h->max_huge_pages_node[nid], buf, nid, i);
> > + h->max_huge_pages -= (h->max_huge_pages_node[nid] - i);
> > + h->max_huge_pages_node[nid] = i;
> > +}
> >
> > static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> > {
> > unsigned long i;
> > nodemask_t *node_alloc_noretry;
> > + bool node_specific_alloc = false;
> > +
> > + /* skip gigantic hugepages allocation if hugetlb_cma enabled */
> > + if (hstate_is_gigantic(h) && hugetlb_cma_size) {
> > + pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
> > + return;
> > + }
> > +
> > + /* do node specific alloc */
> > + for (i = 0; i < nr_online_nodes; i++) {
> > + if (h->max_huge_pages_node[i] > 0) {
> > + hugetlb_hstate_alloc_pages_onenode(h, i);
> > + node_specific_alloc = true;
> > + }
> > + }
> >
> > + if (node_specific_alloc)
> > + return;
> > +
> > + /* bellow will do all node balanced alloc */
>
> below
>
> > if (!hstate_is_gigantic(h)) {
> > /*
> > * Bit mask controlling how hard we retry per-node allocations.
> > @@ -2960,11 +3018,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> >
> > for (i = 0; i < h->max_huge_pages; ++i) {
> > if (hstate_is_gigantic(h)) {
> > - if (hugetlb_cma_size) {
> > - pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
> > - goto free;
> > - }
> > - if (!alloc_bootmem_huge_page(h))
> > + if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE))
> > break;
> > } else if (!alloc_pool_huge_page(h,
> > &node_states[N_MEMORY],
> > @@ -2980,7 +3034,6 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> > h->max_huge_pages, buf, i);
> > h->max_huge_pages = i;
> > }
> > -free:
> > kfree(node_alloc_noretry);
> > }
> >
> > @@ -3671,6 +3724,11 @@ static int __init hugetlb_init(void)
>
> > default_hstate.max_huge_pages =
> > default_hstate_max_huge_pages;
> > +
> > + for (i = 0; i < nr_online_nodes; i++)
> > + if (default_hugepages_in_node[i] > 0)
> > + default_hstate.max_huge_pages_node[i] =
> > + default_hugepages_in_node[i];
>
> Very minor nit. Not necessary to change.
> The 'if (default_hugepages_in_node[i] > 0)' is not really needed. I am
> not sure if any potential speed up by the check would be noticable. You
> need to 'read' every value in the array.
>
> > }
> > }
> >
> > @@ -3731,6 +3789,10 @@ void __init hugetlb_add_hstate(unsigned int order)
> > parsed_hstate = h;
> > }
> >
> > +bool __init __weak node_specific_alloc_support(void)
> > +{
> > + return true;
> > +}
> > /*
> > * hugepages command line processing
> > * hugepages normally follows a valid hugepagsz or default_hugepagsz
> > @@ -3742,6 +3804,10 @@ static int __init hugepages_setup(char *s)
> > {
> > unsigned long *mhp;
> > static unsigned long *last_mhp;
> > + int node = NUMA_NO_NODE;
> > + int count;
> > + unsigned long tmp;
> > + char *p = s;
> >
> > if (!parsed_valid_hugepagesz) {
> > pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s);
> > @@ -3765,8 +3831,40 @@ static int __init hugepages_setup(char *s)
> > return 0;
> > }
> >
> > - if (sscanf(s, "%lu", mhp) <= 0)
> > - *mhp = 0;
> > + while (*p) {
> > + count = 0;
> > + if (sscanf(p, "%lu%n", &tmp, &count) != 1)
> > + goto invalid;
> > + /* Parameter is node format */
> > + if (p[count] == ':') {
> > + if (!node_specific_alloc_support()) {
> > + pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n");
> > + return 0;
> > + }
> > + node = tmp;
> > + p += count + 1;
> > + if (node < 0 || node >= nr_online_nodes)
> > + goto invalid;
> > + /* Parse hugepages */
> > + if (sscanf(p, "%lu%n", &tmp, &count) != 1)
> > + goto invalid;
> > + if (!hugetlb_max_hstate)
> > + default_hugepages_in_node[node] = tmp;
> > + else
> > + parsed_hstate->max_huge_pages_node[node] = tmp;
> > + *mhp += tmp;
> > + /* Go to parse next node*/
> > + if (p[count] == ',')
> > + p += count + 1;
> > + else
> > + break;
> > + } else {
> > + if (p != s)
> > + goto invalid;
> > + *mhp = tmp;
> > + break;
> > + }
> > + }
> >
> > /*
> > * Global state is always initialized later in hugetlb_init.
> > @@ -3779,6 +3877,10 @@ static int __init hugepages_setup(char *s)
> > last_mhp = mhp;
> >
> > return 1;
> > +
> > +invalid:
> > + pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p);
> > + return 0;
> > }
> > __setup("hugepages=", hugepages_setup);
> >
> > @@ -3840,6 +3942,7 @@ __setup("hugepagesz=", hugepagesz_setup);
> > static int __init default_hugepagesz_setup(char *s)
> > {
> > unsigned long size;
> > + int i;
> >
> > parsed_valid_hugepagesz = false;
> > if (parsed_default_hugepagesz) {
> > @@ -3868,6 +3971,10 @@ static int __init default_hugepagesz_setup(char *s)
> > */
> > if (default_hstate_max_huge_pages) {
> > default_hstate.max_huge_pages = default_hstate_max_huge_pages;
> > + for (i = 0; i < nr_online_nodes; i++)
> > + if (default_hugepages_in_node[i] > 0)
> > + default_hstate.max_huge_pages_node[i] =
> > + default_hugepages_in_node[i];
>
> Same minor nit as in hugetlb_init.
>
> > if (hstate_is_gigantic(&default_hstate))
> > hugetlb_hstate_alloc_pages(&default_hstate);
> > default_hstate_max_huge_pages = 0;
> >
>
> --
> Mike Kravetz