diff options
| author | Andrei Vagin <avagin@openvz.org> | 2018-04-10 16:31:19 -0700 | 
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 10:28:33 -0700 | 
| commit | f66406638fffe874c56e7e41106167c5235f251e (patch) | |
| tree | 320407bf48534b78fcf346711e87b3d5131f6fda /fs/proc/array.c | |
| parent | d1be35cb6f96975d792a1535d3fe9b75239065ee (diff) | |
proc: replace seq_printf on seq_putc to speed up /proc/pid/smaps
seq_putc() works much faster than seq_printf()
== Before patch ==
  $ time python test_smaps.py
  real    0m3.828s
  user    0m0.413s
  sys     0m3.408s
== After patch ==
  $ time python test_smaps.py
  real	0m3.405s
  user	0m0.401s
  sys	0m3.003s
== Before patch ==
-   75.51%     4.62%  python   [kernel.kallsyms]    [k] show_smap.isra.33
   - 70.88% show_smap.isra.33
      + 24.82% seq_put_decimal_ull_aligned
      + 19.78% __walk_page_range
      + 12.74% seq_printf
      + 11.08% show_map_vma.isra.23
      + 1.68% seq_puts
== After patch ==
-   69.16%     5.70%  python   [kernel.kallsyms]    [k] show_smap.isra.33
   - 63.46% show_smap.isra.33
      + 25.98% seq_put_decimal_ull_aligned
      + 20.90% __walk_page_range
      + 12.60% show_map_vma.isra.23
        1.56% seq_putc
      + 1.55% seq_puts
Link: http://lkml.kernel.org/r/20180212074931.7227-2-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/array.c')
0 files changed, 0 insertions, 0 deletions
