From: Andi Kleen <andi@firstfloor.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, robert.richter@amd.com
Subject: Re: [PATCH] oprofile: remove double ring buffering
Date: Sat, 20 Mar 2010 05:59:02 +0100 [thread overview]
Message-ID: <20100320045902.GR20695@one.firstfloor.org> (raw)
In-Reply-To: <1269060320.28658.7.camel@localhost>
On Sat, Mar 20, 2010 at 12:45:20AM -0400, Steven Rostedt wrote:
> On Sat, 2010-03-20 at 01:03 +0100, Andi Kleen wrote:
> > [This is currently being tested if it fixes the excessive samples
> > dropping I have been complaining about for some time. Still wanted
> > to post the patch for review.]
> >
> > commit 49e66e8ab54f1114237e6dc24dc32ac912870c41
> > Author: Andi Kleen <ak@linux.intel.com>
> > Date: Fri Mar 19 21:03:48 2010 +0100
> >
> > oprofile: remove double ring buffering
> >
> > oprofile used a double buffer scheme for its cpu event buffer
> > to avoid races on reading with the old lock less ring buffer.
>
> The old ring buffer was not lockless, hence the need for two ring
> buffers because of NMIs. The new ring buffer is lockless.
Thanks. Description fixed.
-Andi
next prev parent reply other threads:[~2010-03-20 4:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-20 0:03 Andi Kleen
2010-03-20 4:45 ` Steven Rostedt
2010-03-20 4:59 ` Andi Kleen [this message]
2010-04-01 1:17 Andi Kleen
2010-04-01 19:02 ` Robert Richter
2010-04-01 19:11 ` Steven Rostedt
2010-04-04 10:01 ` Andi Kleen
2010-04-04 13:07 ` Steven Rostedt
2010-04-22 14:33 ` John Villalovos
2010-04-22 23:04 ` Andrew Morton
2010-04-23 9:00 ` Robert Richter
2010-04-23 15:38 ` Robert Richter
2010-04-23 15:38 ` Robert Richter
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