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Commit 3e79ec7d authored by Vladimir Davydov's avatar Vladimir Davydov Committed by Linus Torvalds
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arch: x86: charge page tables to kmemcg 

Page tables can bite a relatively big chunk off system memory and their
allocations are easy to trigger from userspace, so they should be
accounted to kmemcg.

This patch marks page table allocations as __GFP_ACCOUNT for x86.  Note
we must not charge allocations of kernel page tables, because they can
be shared among processes from different cgroups so accounting them to a
particular one can pin other cgroups for indefinitely long.  So we clear
__GFP_ACCOUNT flag if a page table is allocated for the kernel.

Link: http://lkml.kernel.org/r/7d5c54f6a2bcbe76f03171689440003d87e6c742.1464079538.git.vdavydov@virtuozzo.com


Signed-off-by: default avatarVladimir Davydov <vdavydov@virtuozzo.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5e8d35f8

arch/x86/include/asm/pgalloc.h

+10 −2
Original line number Diff line number Diff line
@@ -81,7 +81,11 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, 
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)

{

	struct page *page;

	page = alloc_pages(GFP_KERNEL |  __GFP_ZERO, 0);

	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;



	if (mm == &init_mm)

		gfp &= ~__GFP_ACCOUNT;

	page = alloc_pages(gfp, 0);

	if (!page)

		return NULL;

	if (!pgtable_pmd_page_ctor(page)) {
@@ -125,7 +129,11 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud) 


static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)

{

	return (pud_t *)get_zeroed_page(GFP_KERNEL);

	gfp_t gfp = GFP_KERNEL_ACCOUNT;



	if (mm == &init_mm)

		gfp &= ~__GFP_ACCOUNT;

	return (pud_t *)get_zeroed_page(gfp);

}



static inline void pud_free(struct mm_struct *mm, pud_t *pud)

arch/x86/mm/pgtable.c

+7 −3
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
#include <asm/fixmap.h>

#include <asm/mtrr.h>



#define PGALLOC_GFP GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO

#define PGALLOC_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | __GFP_ZERO)



#ifdef CONFIG_HIGHPTE

#define PGALLOC_USER_GFP __GFP_HIGHMEM
@@ -18,7 +18,7 @@ gfp_t __userpte_alloc_gfp = PGALLOC_GFP | PGALLOC_USER_GFP; 


pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)

{

	return (pte_t *)__get_free_page(PGALLOC_GFP);

	return (pte_t *)__get_free_page(PGALLOC_GFP & ~__GFP_ACCOUNT);

}



pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
@@ -207,9 +207,13 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[]) 
{

	int i;

	bool failed = false;

	gfp_t gfp = PGALLOC_GFP;



	if (mm == &init_mm)

		gfp &= ~__GFP_ACCOUNT;



	for(i = 0; i < PREALLOCATED_PMDS; i++) {

		pmd_t *pmd = (pmd_t *)__get_free_page(PGALLOC_GFP);

		pmd_t *pmd = (pmd_t *)__get_free_page(gfp);

		if (!pmd)

			failed = true;

		if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {