Commit 27dd768e authored by Sandeep Patil's avatar Sandeep Patil Committed by Linus Torvalds
Browse files

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: 493b0e9d ("mm: add /proc/pid/smaps_rollup")
Signed-off-by: default avatarSandeep Patil <sspatil@android.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 76ce2a80

fs/proc/task_mmu.c

+14 −8
Original line number Diff line number Diff line
@@ -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_size_stats *mss, struct page *page, 
		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, unsigned long addr, 
{

	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, unsigned long addr, 
	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, unsigned long addr, 
{

	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, unsigned long addr, 
		/* 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_area_struct *vma, 
		}

	}

#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) \

CRA Git | Maintained and supported by SUSTech CRA and CCSE