Eric Lee / linux-smarc-t335x-v3.2

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Commit b084d4353ff99d824d3bc5a5c2c22c70b1fba722

Authored by KAMEZAWA Hiroyuki
Committed by Linus Torvalds
1 parent 34e55232e5
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

mm: count swap usage 

A frequent questions from users about memory management is what numbers of
swap ents are user for processes.  And this information will give some
hints to oom-killer.

Besides we can count the number of swapents per a process by scanning
/proc/<pid>/smaps, this is very slow and not good for usual process
information handler which works like 'ps' or 'top'.  (ps or top is now
enough slow..)

This patch adds a counter of swapents to mm_counter and update is at each
swap events.  Information is exported via /proc/<pid>/status file as

[kamezawa@bluextal memory]$ cat /proc/self/status
Name:   cat
State:  R (running)
Tgid:   2910
Pid:    2910
PPid:   2823
TracerPid:      0
Uid:    500     500     500     500
Gid:    500     500     500     500
FDSize: 256
Groups: 500
VmPeak:    82696 kB
VmSize:    82696 kB
VmLck:         0 kB
VmHWM:       432 kB
VmRSS:       432 kB
VmData:      172 kB
VmStk:        84 kB
VmExe:        48 kB
VmLib:      1568 kB
VmPTE:        40 kB
VmSwap:        0 kB <=============== this.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 6 changed files with 23 additions and 7 deletions Side-by-side Diff

Documentation/filesystems/proc.txt
Diff comments   View file @ b084d43
... ... @@ -164,6 +164,7 @@
164 164 VmExe: 68 kB
165 165 VmLib: 1412 kB
166 166 VmPTE: 20 kb
  167 + VmSwap: 0 kB
167 168 Threads: 1
168 169 SigQ: 0/28578
169 170 SigPnd: 0000000000000000
... ... @@ -219,6 +220,7 @@
219 220 VmExe size of text segment
220 221 VmLib size of shared library code
221 222 VmPTE size of page table entries
  223 + VmSwap size of swap usage (the number of referred swapents)
222 224 Threads number of threads
223 225 SigQ number of signals queued/max. number for queue
224 226 SigPnd bitmap of pending signals for the thread
... ... @@ -16,7 +16,7 @@
16 16  
17 17 void task_mem(struct seq_file *m, struct mm_struct *mm)
18 18 {
19   - unsigned long data, text, lib;
  19 + unsigned long data, text, lib, swap;
20 20 unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
21 21  
22 22 /*
... ... @@ -36,6 +36,7 @@
36 36 data = mm->total_vm - mm->shared_vm - mm->stack_vm;
37 37 text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
38 38 lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
  39 + swap = get_mm_counter(mm, MM_SWAPENTS);
39 40 seq_printf(m,
40 41 "VmPeak:\t%8lu kB\n"
41 42 "VmSize:\t%8lu kB\n"
... ... @@ -46,7 +47,8 @@
46 47 "VmStk:\t%8lu kB\n"
47 48 "VmExe:\t%8lu kB\n"
48 49 "VmLib:\t%8lu kB\n"
49   - "VmPTE:\t%8lu kB\n",
  50 + "VmPTE:\t%8lu kB\n"
  51 + "VmSwap:\t%8lu kB\n",
50 52 hiwater_vm << (PAGE_SHIFT-10),
51 53 (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
52 54 mm->locked_vm << (PAGE_SHIFT-10),
... ... @@ -54,7 +56,8 @@
54 56 total_rss << (PAGE_SHIFT-10),
55 57 data << (PAGE_SHIFT-10),
56 58 mm->stack_vm << (PAGE_SHIFT-10), text, lib,
57   - (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10);
  59 + (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10,
  60 + swap << (PAGE_SHIFT-10));
58 61 }
59 62  
60 63 unsigned long task_vsize(struct mm_struct *mm)
include/linux/mm_types.h
Diff comments   View file @ b084d43
... ... @@ -198,6 +198,7 @@
198 198 enum {
199 199 MM_FILEPAGES,
200 200 MM_ANONPAGES,
  201 + MM_SWAPENTS,
201 202 NR_MM_COUNTERS
202 203 };
203 204  
... ... @@ -679,7 +679,9 @@
679 679 &src_mm->mmlist);
680 680 spin_unlock(&mmlist_lock);
681 681 }
682   - if (is_write_migration_entry(entry) &&
  682 + if (likely(!non_swap_entry(entry)))
  683 + rss[MM_SWAPENTS]++;
  684 + else if (is_write_migration_entry(entry) &&
683 685 is_cow_mapping(vm_flags)) {
684 686 /*
685 687 * COW mappings require pages in both parent
... ... @@ -974,9 +976,14 @@
974 976 if (pte_file(ptent)) {
975 977 if (unlikely(!(vma->vm_flags & VM_NONLINEAR)))
976 978 print_bad_pte(vma, addr, ptent, NULL);
977   - } else if
978   - (unlikely(!free_swap_and_cache(pte_to_swp_entry(ptent))))
979   - print_bad_pte(vma, addr, ptent, NULL);
  979 + } else {
  980 + swp_entry_t entry = pte_to_swp_entry(ptent);
  981 +
  982 + if (!non_swap_entry(entry))
  983 + rss[MM_SWAPENTS]--;
  984 + if (unlikely(!free_swap_and_cache(entry)))
  985 + print_bad_pte(vma, addr, ptent, NULL);
  986 + }
980 987 pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
981 988 } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0));
982 989  
... ... @@ -2692,6 +2699,7 @@
2692 2699 */
2693 2700  
2694 2701 inc_mm_counter_fast(mm, MM_ANONPAGES);
  2702 + dec_mm_counter_fast(mm, MM_SWAPENTS);
2695 2703 pte = mk_pte(page, vma->vm_page_prot);
2696 2704 if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) {
2697 2705 pte = maybe_mkwrite(pte_mkdirty(pte), vma);
... ... @@ -840,6 +840,7 @@
840 840 spin_unlock(&mmlist_lock);
841 841 }
842 842 dec_mm_counter(mm, MM_ANONPAGES);
  843 + inc_mm_counter(mm, MM_SWAPENTS);
843 844 } else if (PAGE_MIGRATION) {
844 845 /*
845 846 * Store the pfn of the page in a special migration
... ... @@ -840,6 +840,7 @@
840 840 goto out;
841 841 }
842 842  
  843 + dec_mm_counter(vma->vm_mm, MM_SWAPENTS);
843 844 inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
844 845 get_page(page);
845 846 set_pte_at(vma->vm_mm, addr, pte,