[RFC PATCH 07/16] mm: stats: make smap stats understand PUD THPs.

From: Zi Yan
Date: Wed Sep 02 2020 - 14:08:37 EST


From: Zi Yan <ziy@xxxxxxxxxx>

Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
fs/proc/task_mmu.c | 63 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 58 insertions(+), 5 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 7fc9b3cc48d3..2ff80a9c8b57 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -430,10 +430,9 @@ static void smaps_page_accumulate(struct mem_size_stats *mss,
}

static void smaps_account(struct mem_size_stats *mss, struct page *page,
- bool compound, bool young, bool dirty, bool locked)
+ unsigned long size, bool young, bool dirty, bool locked)
{
- int i, nr = compound ? compound_nr(page) : 1;
- unsigned long size = nr * PAGE_SIZE;
+ int i, nr = size / PAGE_SIZE;

/*
* First accumulate quantities that depend only on |size| and the type
@@ -536,7 +535,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
if (!page)
return;

- smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
+ smaps_account(mss, page, PAGE_SIZE, pte_young(*pte), pte_dirty(*pte), locked);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -567,8 +566,44 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
/* pass */;
else
mss->file_thp += HPAGE_PMD_SIZE;
- smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
+ smaps_account(mss, page, HPAGE_PMD_SIZE, pmd_young(*pmd),
+ pmd_dirty(*pmd), locked);
}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void smaps_pud_entry(pud_t *pud, unsigned long addr,
+ struct mm_walk *walk)
+{
+ struct mem_size_stats *mss = walk->private;
+ struct vm_area_struct *vma = walk->vma;
+ bool locked = !!(vma->vm_flags & VM_LOCKED);
+ struct page *page = NULL;
+
+ if (pud_present(*pud)) {
+ /* FOLL_DUMP will return -EFAULT on huge zero page */
+ page = follow_trans_huge_pud(vma, addr, pud, FOLL_DUMP);
+ }
+ if (IS_ERR_OR_NULL(page))
+ return;
+ if (PageAnon(page))
+ mss->anonymous_thp += HPAGE_PUD_SIZE;
+ else if (PageSwapBacked(page))
+ mss->shmem_thp += HPAGE_PUD_SIZE;
+ else if (is_zone_device_page(page))
+ /* pass */;
+ else
+ mss->file_thp += HPAGE_PUD_SIZE;
+ smaps_account(mss, page, HPAGE_PUD_SIZE, pud_young(*pud),
+ pud_dirty(*pud), locked);
+}
+#else
+static void smaps_pud_entry(pud_t *pud, unsigned long addr,
+ struct mm_walk *walk)
+{
+}
+#endif
+
+
#else
static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
struct mm_walk *walk)
@@ -576,6 +611,23 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
}
#endif

+static int smaps_pud_range(pud_t *pud, unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ spinlock_t *ptl;
+
+ ptl = pud_trans_huge_lock(pud, vma);
+ if (ptl) {
+ smaps_pud_entry(pud, addr, walk);
+ spin_unlock(ptl);
+ walk->action = ACTION_CONTINUE;
+ }
+
+ cond_resched();
+ return 0;
+}
+
static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
@@ -713,6 +765,7 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
#endif /* HUGETLB_PAGE */

static const struct mm_walk_ops smaps_walk_ops = {
+ .pud_entry = smaps_pud_range,
.pmd_entry = smaps_pte_range,
.hugetlb_entry = smaps_hugetlb_range,
};
--
2.28.0