From: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Subject: thp: use mm_file_counter to determine update which rss counter
Since eca56ff906b ("mm, shmem: add internal shmem resident memory
accounting"), MM_SHMEMPAGES is added to separate the shmem accounting from
regular files. So, all shmem pages should be accounted to MM_SHMEMPAGES
instead of MM_FILEPAGES.
And, normal 4K shmem pages have been accounted to MM_SHMEMPAGES, so shmem
thp pages should be not treated differently. Account them to
MM_SHMEMPAGES via mm_counter_file() since shmem pages are swap backed to
keep consistent with normal 4K shmem pages.
This will not change the rss counter of processes since shmem pages are
still a part of it.
The /proc/pid/status and /proc/pid/statm counters will however be more
accurate wrt shmem usage, as originally intended. And as eca56ff906bdd
("mm, shmem: add internal shmem resident memory accounting") mentioned,
oom also could report more accurate "shmem-rss".
Link: http://lkml.kernel.org/r/1529442518-17398-1-git-send-email-yang.shi@xxxxxxxxxxxxxxxxx
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 4 ++--
mm/memory.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
--- a/mm/huge_memory.c~thp-use-mm_file_counter-to-determine-update-which-rss-counter
+++ a/mm/huge_memory.c
@@ -1740,7 +1740,7 @@ int zap_huge_pmd(struct mmu_gather *tlb,
} else {
if (arch_needs_pgtable_deposit())
zap_deposited_table(tlb->mm, pmd);
- add_mm_counter(tlb->mm, MM_FILEPAGES, -HPAGE_PMD_NR);
+ add_mm_counter(tlb->mm, mm_counter_file(page), -HPAGE_PMD_NR);
}
spin_unlock(ptl);
@@ -2090,7 +2090,7 @@ static void __split_huge_pmd_locked(stru
SetPageReferenced(page);
page_remove_rmap(page, true);
put_page(page);
- add_mm_counter(mm, MM_FILEPAGES, -HPAGE_PMD_NR);
+ add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR);
return;
} else if (is_huge_zero_pmd(*pmd)) {
/*
--- a/mm/memory.c~thp-use-mm_file_counter-to-determine-update-which-rss-counter
+++ a/mm/memory.c
@@ -3400,7 +3400,7 @@ static int do_set_pmd(struct vm_fault *v
if (write)
entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
- add_mm_counter(vma->vm_mm, MM_FILEPAGES, HPAGE_PMD_NR);
+ add_mm_counter(vma->vm_mm, mm_counter_file(page), HPAGE_PMD_NR);
page_add_file_rmap(page, true);
/*
* deposit and withdraw with pmd lock held
_
