tree 0dd46f10d70f7814d622f1862ba6bf1c1cf4e18d
parent 9137fb28ac74d05eb66d1d8e6778eaa14e6fed43
author Peter Zijlstra <a.p.zijlstra@chello.nl> 1302376662 +0200
committer Ingo Molnar <mingo@elte.hu> 1306598472 +0200

perf: Optimize event scheduling locking

Currently we only hold one ctx->lock at a time, which results in us
flipping back and forth between cpuctx->ctx.lock and task_ctx->lock.

Avoid this and gain large atomic regions by holding both locks. We
nest the task lock inside the cpu lock, since with task scheduling we
might have to change task ctx while holding the cpu ctx lock.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110409192141.769881865@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>