summaryrefslogtreecommitdiffstats
path: root/sound/oss/soundcard.c
diff options
context:
space:
mode:
authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2012-03-23 23:02:54 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-24 00:58:42 +0100
commitbda7bad62bc4c4e0783348e8db51abe094153c56 (patch)
treec62650a3da656ba18aebe170df7d554158ae5fc5 /sound/oss/soundcard.c
parentprocfs: add num_to_str() to speed up /proc/stat (diff)
downloadlinux-bda7bad62bc4c4e0783348e8db51abe094153c56.tar.xz
linux-bda7bad62bc4c4e0783348e8db51abe094153c56.zip
procfs: speed up /proc/pid/stat, statm
Process accounting applications as top, ps visit some files under /proc/<pid>. With seq_put_decimal_ull(), we can optimize /proc/<pid>/stat and /proc/<pid>/statm files. This patch adds - seq_put_decimal_ll() for signed values. - allow delimiter == 0. - convert seq_printf() to seq_put_decimal_ull/ll in /proc/stat, statm. Test result on a system with 2000+ procs. Before patch: [kamezawa@bluextal test]$ top -b -n 1 | wc -l 2223 [kamezawa@bluextal test]$ time top -b -n 1 > /dev/null real 0m0.675s user 0m0.044s sys 0m0.121s [kamezawa@bluextal test]$ time ps -elf > /dev/null real 0m0.236s user 0m0.056s sys 0m0.176s After patch: kamezawa@bluextal ~]$ time top -b -n 1 > /dev/null real 0m0.657s user 0m0.052s sys 0m0.100s [kamezawa@bluextal ~]$ time ps -elf > /dev/null real 0m0.198s user 0m0.050s sys 0m0.145s Considering top, ps tend to scan /proc periodically, this will reduce cpu consumption by top/ps to some extent. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound/oss/soundcard.c')
0 files changed, 0 insertions, 0 deletions