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author | Andrei Vagin <avagin@openvz.org> | 2018-04-10 16:31:23 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 10:28:33 -0700 |
commit | 48dffbf82d2f17bc6dd3c2b7fd733738ea567914 (patch) | |
tree | 40e7facfdd53bd3157622b9a03d61802b684319f /fs/proc | |
parent | f66406638fffe874c56e7e41106167c5235f251e (diff) | |
download | linux-48dffbf82d2f17bc6dd3c2b7fd733738ea567914.tar.bz2 |
proc: optimize single-symbol delimiters to spead up seq_put_decimal_ull
A delimiter is a string which is printed before a number. A
syngle-symbol delimiters can be printed by set_putc() and this works
faster than printing by set_puts().
== test_proc.c
int main(int argc, char **argv)
{
int n, i, fd;
char buf[16384];
n = atoi(argv[1]);
for (i = 0; i < n; i++) {
fd = open(argv[2], O_RDONLY);
if (fd < 0)
return 1;
if (read(fd, buf, sizeof(buf)) <= 0)
return 1;
close(fd);
}
return 0;
}
==
$ time ./test_proc 1000000 /proc/1/stat
== Before patch ==
real 0m3.820s
user 0m0.337s
sys 0m3.394s
== After patch ==
real 0m3.110s
user 0m0.324s
sys 0m2.700s
Link: http://lkml.kernel.org/r/20180212074931.7227-3-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Cc: 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')
0 files changed, 0 insertions, 0 deletions