| Message ID | 1529442518-17398-1-git-send-email-yang.shi@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/19/2018 11:08 PM, Yang Shi wrote: > Since commit eca56ff906bdd0239485e8b47154a6e73dd9a2f3 ("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. Accouting 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. <Andrew>So what are the user-visible effects of the patch then?</Andrew> Let's add this?: The /proc/pid/status and /proc/pid/statm counters will however be more accurate wrt shmem usage, as originally intended. > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> > Cc: Hugh Dickins <hughd@google.com> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Good catch, thanks. I guess the discrepancy happened due to the thp-tmpfs patchset existing externally for a long time and number of iterations, while commit eca56ff906bdd was merged, and nobody noticed that the thp case added more MM_FILEPAGES users. Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/huge_memory.c | 4 ++-- > mm/memory.c | 2 +- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 1cd7c1a..2687f7c 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1740,7 +1740,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, > } 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); > @@ -2088,7 +2088,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, > 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)) { > /* > diff --git a/mm/memory.c b/mm/memory.c > index 7206a63..4a2f2a8 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3372,7 +3372,7 @@ static int do_set_pmd(struct vm_fault *vmf, struct page *page) > 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 >
On 6/20/18 3:57 AM, Vlastimil Babka wrote: > On 06/19/2018 11:08 PM, Yang Shi wrote: >> Since commit eca56ff906bdd0239485e8b47154a6e73dd9a2f3 ("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. Accouting 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. > <Andrew>So what are the user-visible effects of the patch then?</Andrew> > > Let's add this?: > > The /proc/pid/status and /proc/pid/statm counters will however be more > accurate wrt shmem usage, as originally intended. Thanks. Yes, other than this as commit eca56ff906bdd0239485e8b47154a6e73dd9a2f3 mentioned, oom also could report more accurate "shmem-rss" > >> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Good catch, thanks. I guess the discrepancy happened due to the > thp-tmpfs patchset existing externally for a long time and number of > iterations, while commit eca56ff906bdd was merged, and nobody noticed > that the thp case added more MM_FILEPAGES users. > > Acked-by: Vlastimil Babka <vbabka@suse.cz> Thanks. Yang > >> --- >> mm/huge_memory.c | 4 ++-- >> mm/memory.c | 2 +- >> 2 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 1cd7c1a..2687f7c 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -1740,7 +1740,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, >> } 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); >> @@ -2088,7 +2088,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, >> 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)) { >> /* >> diff --git a/mm/memory.c b/mm/memory.c >> index 7206a63..4a2f2a8 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -3372,7 +3372,7 @@ static int do_set_pmd(struct vm_fault *vmf, struct page *page) >> 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 >>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1cd7c1a..2687f7c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1740,7 +1740,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, } 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); @@ -2088,7 +2088,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, 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)) { /* diff --git a/mm/memory.c b/mm/memory.c index 7206a63..4a2f2a8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3372,7 +3372,7 @@ static int do_set_pmd(struct vm_fault *vmf, struct page *page) 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
Since commit eca56ff906bdd0239485e8b47154a6e73dd9a2f3 ("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. Accouting 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. Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- mm/huge_memory.c | 4 ++-- mm/memory.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-)