+ mm-proc-smaps_rollup-fix-pss_locked-calculation.patch added to -mm tree

* + mm-proc-smaps_rollup-fix-pss_locked-calculation.patch added to -mm tree
@ 2019-02-08 22:18 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2019-02-08 22:18 UTC (permalink / raw)
  To: mm-commits, vbabka, stable, dancol, adobriyan, sspatil


The patch titled
     Subject: mm: proc: smaps_rollup: fix pss_locked calculation
has been added to the -mm tree.  Its filename is
     mm-proc-smaps_rollup-fix-pss_locked-calculation.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-proc-smaps_rollup-fix-pss_locked-calculation.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-proc-smaps_rollup-fix-pss_locked-calculation.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Sandeep Patil <sspatil@android.com>
Subject: mm: proc: smaps_rollup: fix pss_locked calculation

The 'pss_locked' field of smaps_rollup was being calculated incorrectly. 
It accumulated the current pss everytime a locked VMA was found.  Fix that
by adding to 'pss_locked' the same time as that of 'pss' if the vma being
walked is locked.

Link: http://lkml.kernel.org/r/20190203065425.14650-1-sspatil@android.com
Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup")
Signed-off-by: Sandeep Patil <sspatil@android.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Colascione <dancol@google.com>
Cc: <stable@vger.kernel.org>	[4.14.x, 4.19.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/task_mmu.c |   22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

--- a/fs/proc/task_mmu.c~mm-proc-smaps_rollup-fix-pss_locked-calculation
+++ a/fs/proc/task_mmu.c
@@ -423,7 +423,7 @@ struct mem_size_stats {
 };
 
 static void smaps_account(struct mem_size_stats *mss, struct page *page,
-		bool compound, bool young, bool dirty)
+		bool compound, bool young, bool dirty, bool locked)
 {
 	int i, nr = compound ? 1 << compound_order(page) : 1;
 	unsigned long size = nr * PAGE_SIZE;
@@ -450,24 +450,31 @@ static void smaps_account(struct mem_siz
 		else
 			mss->private_clean += size;
 		mss->pss += (u64)size << PSS_SHIFT;
+		if (locked)
+			mss->pss_locked += (u64)size << PSS_SHIFT;
 		return;
 	}
 
 	for (i = 0; i < nr; i++, page++) {
 		int mapcount = page_mapcount(page);
+		unsigned long pss = (PAGE_SIZE << PSS_SHIFT);
 
 		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;
+			mss->pss += pss / mapcount;
+			if (locked)
+				mss->pss_locked += pss / mapcount;
 		} else {
 			if (dirty || PageDirty(page))
 				mss->private_dirty += PAGE_SIZE;
 			else
 				mss->private_clean += PAGE_SIZE;
-			mss->pss += PAGE_SIZE << PSS_SHIFT;
+			mss->pss += pss;
+			if (locked)
+				mss->pss_locked += pss;
 		}
 	}
 }
@@ -490,6 +497,7 @@ static void smaps_pte_entry(pte_t *pte,
 {
 	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 (pte_present(*pte)) {
@@ -532,7 +540,7 @@ static void smaps_pte_entry(pte_t *pte,
 	if (!page)
 		return;
 
-	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
+	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -541,6 +549,7 @@ static void smaps_pmd_entry(pmd_t *pmd,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
+	bool locked = !!(vma->vm_flags & VM_LOCKED);
 	struct page *page;
 
 	/* FOLL_DUMP will return -EFAULT on huge zero page */
@@ -555,7 +564,7 @@ static void smaps_pmd_entry(pmd_t *pmd,
 		/* pass */;
 	else
 		VM_BUG_ON_PAGE(1, page);
-	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
+	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
 }
 #else
 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -737,11 +746,8 @@ static void smap_gather_stats(struct vm_
 		}
 	}
 #endif
-
 	/* mmap_sem is held in m_start */
 	walk_page_vma(vma, &smaps_walk);
-	if (vma->vm_flags & VM_LOCKED)
-		mss->pss_locked += mss->pss;
 }
 
 #define SEQ_PUT_DEC(str, val) \
_

Patches currently in -mm which might be from sspatil@android.com are

mm-proc-smaps_rollup-fix-pss_locked-calculation.patch


^ permalink raw reply	[flat|nested] 2+ messages in thread