lkml.org 
[lkml]   [2016]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact
From
Date
Thank you Dimtry for sharing the patches.

Update from my tests:
Use-case: Android application launches.

I tested the patches on android N build, i see max latency ~7ms.
In my tests, the wait is due to: copy_process(fork.c) blocks all threads
in __cgroup_procs_write including threads which are not part of the
forking process's thread-group.

Dimtry had provided a hack patch which reverts to per-process rw-sem
which had max latency of ~2ms.

android user-space binder library does 2 cgroup write operations per
transaction, apart from the copy_process(fork.c) wait, i see pre-emption
in _cgroup_procs_write causing waits.

Thanks.

--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

\
 
 \ /
  Last update: 2016-09-17 09:56    [W:0.149 / U:1.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site