Messages in this thread | | | From | Linus Walleij <> | Date | Wed, 20 Dec 2017 10:34:29 +0100 | Subject | Re: [PATCH 3/4] gpio: sysfs: don't use sprintf() for 'value' attribute |
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On Mon, Dec 18, 2017 at 11:08 AM, Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> 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>
Patch applied.
Yours, Linus Walleij
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