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Christophe Leroy
7a94b88cb7
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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.