0cc75888da
1. In latencytop source codes, we only have such calling chain:
account_scheduler_latency(struct task_struct *task, int usecs, int inter)
{
if (unlikely(latencytop_enabled)) /* the outtermost check */
__account_scheduler_latency(task, usecs, inter);
}
__account_scheduler_latency
account_global_scheduler_latency
if (!latencytop_enabled)
So, the inner check for latencytop_enabled is not necessary at all.
2. In clear_all_latency_tracing and now is called
clear_tsk_latency_tracing the check for latencytop_enabled is redundant
and buggy to some extent.
We have no reason to refuse clearing the /proc/$pid/latency if
latencytop_enabled is set to 0, considering that if we use latencytop
manually by echo 0 > /proc/sys/kernel/latencytop, then we want to clear
/proc/$pid/latency and failed.
Also we don't have such check in brother function
clear_global_latency_tracing.
Notes: These changes are only visible to users who set
CONFIG_LATENCYTOP and won't change user tool latencytop's behavior.
Link: http://lkml.kernel.org/r/20190226114602.16902-2-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.