linux-kernel - [PATCH 0/2] locking/percpu-rwsem: Optimizations/tweaks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 14 Jul 2016 20:25:45 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	mingo@...nel.org, linux-kernel@...r.kernel.org
Cc:	oleg@...hat.com, tj@...nel.org, paulmck@...ux.vnet.ibm.com,
	john.stultz@...aro.org, dimitrysh@...gle.com, romlem@...gle.com,
	ccross@...gle.com, tkjos@...gle.com, peterz@...radead.org
Subject: [PATCH 0/2] locking/percpu-rwsem: Optimizations/tweaks

As reported by John and Dmitry, Android tickles bad behaviour in
cgroup_threadgroup_rwsem.

These two patches attempt to address the issue by optimizing the percpu-rwsem
slow path and second add a bias knob to the percpu-rwsem that allows disabling
the fast path which improves writer latency by getting rid of a
synchronize_sched() call.

---
 fs/super.c                    |   3 +-
 include/linux/percpu-rwsem.h  |  96 +++++++++++++++--
 kernel/cgroup.c               |   2 +-
 kernel/locking/percpu-rwsem.c | 246 +++++++++++++++++++++++++-----------------
 4 files changed, 239 insertions(+), 108 deletions(-)