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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2017-11-15 17:35:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 18:21:04 -0800 |
| commit | af5b0f6a09e42c9f4fa87735f2a366748767b686 (patch) | |
| tree | ac9a7992f92ae5a7902805e980bb31e8edc4555b /fs | |
| parent | c4812909f5d5a9b7f1c85a2d95be388a066cda52 (diff) | |
| download | linux-af5b0f6a09e42c9f4fa87735f2a366748767b686.tar.gz | |
mm: consolidate page table accounting
Currently, we account page tables separately for each page table level, but that's redundant -- we only make use of total memory allocated to page tables for oom_badness calculation. We also provide the information to userspace, but it has dubious value there too. This patch switches page table accounting to single counter. mm->pgtables_bytes is now used to account all page table levels. We use bytes, because page table size for different levels of page table tree may be different. The change has user-visible effect: we don't have VmPMD and VmPUD reported in /proc/[pid]/status. Not sure if anybody uses them. (As alternative, we can always report 0 kB for them.) OOM-killer report is also slightly changed: we now report pgtables_bytes instead of nr_ptes, nr_pmd, nr_puds. Apart from reducing number of counters per-mm, the benefit is that we now calculate oom_badness() more correctly for machines which have different size of page tables depending on level or where page tables are less than a page in size. The only downside can be debuggability because we do not know which page table level could leak. But I do not remember many bugs that would be caught by separate counters so I wouldn't lose sleep over this. [akpm@linux-foundation.org: fix mm/huge_memory.c] Link: http://lkml.kernel.org/r/20171006100651.44742-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> [kirill.shutemov@linux.intel.com: fix build] Link: http://lkml.kernel.org/r/20171016150113.ikfxy3e7zzfvsr4w@black.fi.intel.com Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/task_mmu.c | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9bd2a0294ac1..875231c36cb3 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -26,7 +26,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) { - unsigned long text, lib, swap, ptes, pmds, puds, anon, file, shmem; + unsigned long text, lib, swap, anon, file, shmem; unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; anon = get_mm_counter(mm, MM_ANONPAGES); @@ -50,9 +50,6 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10; lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text; swap = get_mm_counter(mm, MM_SWAPENTS); - ptes = PTRS_PER_PTE * sizeof(pte_t) * mm_nr_ptes(mm); - pmds = PTRS_PER_PMD * sizeof(pmd_t) * mm_nr_pmds(mm); - puds = PTRS_PER_PUD * sizeof(pud_t) * mm_nr_puds(mm); seq_printf(m, "VmPeak:\t%8lu kB\n" "VmSize:\t%8lu kB\n" @@ -68,8 +65,6 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) "VmExe:\t%8lu kB\n" "VmLib:\t%8lu kB\n" "VmPTE:\t%8lu kB\n" - "VmPMD:\t%8lu kB\n" - "VmPUD:\t%8lu kB\n" "VmSwap:\t%8lu kB\n", hiwater_vm << (PAGE_SHIFT-10), total_vm << (PAGE_SHIFT-10), @@ -82,9 +77,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) shmem << (PAGE_SHIFT-10), mm->data_vm << (PAGE_SHIFT-10), mm->stack_vm << (PAGE_SHIFT-10), text, lib, - ptes >> 10, - pmds >> 10, - puds >> 10, + mm_pgtables_bytes(mm) >> 10, swap << (PAGE_SHIFT-10)); hugetlb_report_usage(m, mm); } |