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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2017-12-18 11:08:33 +0100 |
|---|---|---|
| committer |   Linus Walleij <linus.walleij@linaro.org> | 2017-12-20 10:34:01 +0100 |
| commit | 7a94b88cb7087aa3184161bedccfea25e5502c62 (patch) | |
| tree | 834dd94fd037c9b6edb3ba890e38df1af6cb77e1 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | gpio: sysfs: correct error handling on 'value' attribute read. (diff) | |
| download | wireguard-linux-7a94b88cb7087aa3184161bedccfea25e5502c62.tar.xz wireguard-linux-7a94b88cb7087aa3184161bedccfea25e5502c62.zip | |
gpio: sysfs: don't use sprintf() for 'value' attribute
A bench with 'perf record' shows that most of time spent in value_show()
is spent in sprintf()
--42.41%--sysfs_kf_read
|
|--39.73%--dev_attr_show
| |
| |--38.23%--value_show
| | |
| | |--29.22%--sprintf
| | |
| | |--2.94%--gpiod_get_value_cansleep
| | |
value_show() only returns "0\n" or "1\n", therefore the use of
sprintf() can be avoided
With this patch we get the following result with 'perf record'
--13.89%--sysfs_kf_read
|
|--10.72%--dev_attr_show
| |
| |--9.44%--value_show
| | |
| | |--4.61%--gpiod_get_value_cansleep
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions