Messages in this thread | | | Subject | Re: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact | From | Om Dhyade <> | Date | Fri, 12 Aug 2016 18:44:28 -0700 |
| |
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
| |