linux-kernel - [for-next][PATCH 0/2] tracing: Remove bottle neck mutex in splicing from ring buffer

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Date:	Tue, 23 Dec 2014 11:13:40 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	linux-kernel@...r.kernel.org
Cc:	Ingo Molnar <mingo@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [for-next][PATCH 0/2] tracing: Remove bottle neck mutex in splicing from ring buffer

While profiling with trace-cmd, I found that the there was a global
mutex being taken in the per-cpu splice code. This was slowing down
the recording and causing more missed events than necessary.

By adding a ref count to the tracer, and preventing the tracer from
changing when the ref count is non-zero (when a trace file is opened)
we can remove the taking of the trace_types_lock mutex from the
splice page and speed things up a bit.

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: d716ff71dd12bc6328f84a9ec1c3647daf01c827

Steven Rostedt (Red Hat) (2):
      tracing: Add ref count to tracer for when they are being read by pipe
      tracing: Remove taking of trace_types_lock in pipe files

----
 kernel/trace/trace.c | 126 ++++++++++++++++++---------------------------------
 kernel/trace/trace.h |   1 +
 2 files changed, 44 insertions(+), 83 deletions(-)

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