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 | |
| parent | d1be35cb6f96975d792a1535d3fe9b75239065ee (diff) | |
| download | op-kernel-dev-f66406638fffe874c56e7e41106167c5235f251e.zip op-kernel-dev-f66406638fffe874c56e7e41106167c5235f251e.tar.gz | |
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')
| -rw-r--r-- | fs/proc/task_mmu.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 3026fed..65ae546 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -688,8 +688,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) if (!mnemonics[i][0]) continue; if (vma->vm_flags & (1UL << i)) { - seq_printf(m, "%c%c ", - mnemonics[i][0], mnemonics[i][1]); + seq_putc(m, mnemonics[i][0]); + seq_putc(m, mnemonics[i][1]); + seq_putc(m, ' '); } } seq_putc(m, '\n'); |
