diff options
| -rw-r--r-- | fs/proc/task_mmu.c | 47 |
1 files changed, 31 insertions, 16 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index a353b4c6e86e..b74e7dec37dd 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -466,9 +466,10 @@ struct mem_size_stats { }; static void smaps_account(struct mem_size_stats *mss, struct page *page, - unsigned long size, bool young, bool dirty) + bool compound, bool young, bool dirty) { - int mapcount; + int i, nr = compound ? HPAGE_PMD_NR : 1; + unsigned long size = nr * PAGE_SIZE; if (PageAnon(page)) mss->anonymous += size; @@ -477,23 +478,37 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page, /* Accumulate the size in pages that have been accessed. */ if (young || page_is_young(page) || PageReferenced(page)) mss->referenced += size; - mapcount = page_mapcount(page); - if (mapcount >= 2) { - u64 pss_delta; - if (dirty || PageDirty(page)) - mss->shared_dirty += size; - else - mss->shared_clean += size; - pss_delta = (u64)size << PSS_SHIFT; - do_div(pss_delta, mapcount); - mss->pss += pss_delta; - } else { + /* + * page_count(page) == 1 guarantees the page is mapped exactly once. + * If any subpage of the compound page mapped with PTE it would elevate + * page_count(). + */ + if (page_count(page) == 1) { if (dirty || PageDirty(page)) mss->private_dirty += size; else mss->private_clean += size; mss->pss += (u64)size << PSS_SHIFT; + return; + } + + for (i = 0; i < nr; i++, page++) { + int mapcount = page_mapcount(page); + + if (mapcount >= 2) { + if (dirty || PageDirty(page)) + mss->shared_dirty += PAGE_SIZE; + else + mss->shared_clean += PAGE_SIZE; + mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount; + } else { + if (dirty || PageDirty(page)) + mss->private_dirty += PAGE_SIZE; + else + mss->private_clean += PAGE_SIZE; + mss->pss += PAGE_SIZE << PSS_SHIFT; + } } } @@ -554,7 +569,8 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr, if (!page) return; - smaps_account(mss, page, PAGE_SIZE, pte_young(*pte), pte_dirty(*pte)); + + smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte)); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -570,8 +586,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, if (IS_ERR_OR_NULL(page)) return; mss->anonymous_thp += HPAGE_PMD_SIZE; - smaps_account(mss, page, HPAGE_PMD_SIZE, - pmd_young(*pmd), pmd_dirty(*pmd)); + smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd)); } #else static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, |