Messages in this thread Patch in this message | | | Date | Wed, 26 Sep 2012 19:29:58 -0700 (PDT) | From | David Rientjes <> | Subject | [patch] mm, thp: fix mlock statistics |
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NR_MLOCK is only accounted in single page units: there's no logic to handle transparent hugepages. This patch checks the appropriate number of pages to adjust the statistics by so that the correct amount of memory is reflected.
Currently:
$ grep Mlocked /proc/meminfo Mlocked: 19636 kB
#define MAP_SIZE (4 << 30) /* 4GB */
void *ptr = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); mlock(ptr, MAP_SIZE);
$ grep Mlocked /proc/meminfo Mlocked: 29844 kB
munlock(ptr, MAP_SIZE);
$ grep Mlocked /proc/meminfo Mlocked: 19636 kB
And with this patch:
$ grep Mlock /proc/meminfo Mlocked: 19636 kB
mlock(ptr, MAP_SIZE);
$ grep Mlock /proc/meminfo Mlocked: 4213664 kB
munlock(ptr, MAP_SIZE);
$ grep Mlock /proc/meminfo Mlocked: 19636 kB
Reported-by: Hugh Dickens <hughd@google.com> Signed-off-by: David Rientjes <rientjes@google.com> --- mm/internal.h | 3 ++- mm/mlock.c | 6 ++++-- mm/page_alloc.c | 2 +- 3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h --- a/mm/internal.h +++ b/mm/internal.h @@ -180,7 +180,8 @@ static inline int mlocked_vma_newpage(struct vm_area_struct *vma, return 0; if (!TestSetPageMlocked(page)) { - inc_zone_page_state(page, NR_MLOCK); + mod_zone_page_state(page_zone(page), NR_MLOCK, + hpage_nr_pages(page)); count_vm_event(UNEVICTABLE_PGMLOCKED); } return 1; diff --git a/mm/mlock.c b/mm/mlock.c --- a/mm/mlock.c +++ b/mm/mlock.c @@ -81,7 +81,8 @@ void mlock_vma_page(struct page *page) BUG_ON(!PageLocked(page)); if (!TestSetPageMlocked(page)) { - inc_zone_page_state(page, NR_MLOCK); + mod_zone_page_state(page_zone(page), NR_MLOCK, + hpage_nr_pages(page)); count_vm_event(UNEVICTABLE_PGMLOCKED); if (!isolate_lru_page(page)) putback_lru_page(page); @@ -108,7 +109,8 @@ void munlock_vma_page(struct page *page) BUG_ON(!PageLocked(page)); if (TestClearPageMlocked(page)) { - dec_zone_page_state(page, NR_MLOCK); + mod_zone_page_state(page_zone(page), NR_MLOCK, + -hpage_nr_pages(page)); if (!isolate_lru_page(page)) { int ret = SWAP_AGAIN; diff --git a/mm/page_alloc.c b/mm/page_alloc.c --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -604,7 +604,7 @@ out: */ static inline void free_page_mlock(struct page *page) { - __dec_zone_page_state(page, NR_MLOCK); + __mod_zone_page_state(page_zone(page), NR_MLOCK, -hpage_nr_pages(page)); __count_vm_event(UNEVICTABLE_MLOCKFREED); }
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