| Message ID | 20180212074931.7227-2-avagin@openvz.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Feb 11, 2018 at 11:49:29PM -0800, Andrei Vagin wrote: > 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, ' '); Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 3026feda0432..65ae54659833 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');
seq_putc() works much faster than seq_printf() $ time python test_smaps.py == Before patch == real 0m3.828s user 0m0.413s sys 0m3.408s == After patch == 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 Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> --- fs/proc/task_mmu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)