From: Peter Zijlstra <peterz@infradead.org>
To: Harald Gustafsson <hgu1972@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Frederic Weisbecker <fweisbec@gmail.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Harald Gustafsson <harald.gustafsson@ericsson.com>,
Song Yuan <song.yuan@ericsson.com>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: perf events over (net) console?
Date: Thu, 09 Sep 2010 14:47:33 +0200 [thread overview]
Message-ID: <1284036453.402.11.camel@laptop> (raw)
In-Reply-To: <AANLkTikuqHFdOoiB4ejRygi3EV3p4HN2jgjJwM6Sw+31@mail.gmail.com>
On Thu, 2010-09-09 at 14:31 +0200, Harald Gustafsson wrote:
> Sorry for being daft...
No worries, I'm sure we all qualify at times ;-)
> >> >
> >> > You need a process context anyway to read the data and send it to
> >> > whatever place you want it.
> >> >
> >> > Putting that in-kernel serves no purpose what so ever.
> >>
> >> But if we bring the splice support, that can be done with minimal
> >> userspace noise. Plus that would work with the usual sockets but not
> >> limited to that.
> >
> > Yes. If we can transform the data over the network without it touching
> > disk, then that would be a sufficiently 'does not disturb other tasks'
> > measurement method.
>
> Thanks for the pointers to more information, and yes my thoughts was
> more about avoiding the data copy then avoiding any processing context
> at all.
Right, currently you get a single copy with mmap() + write(), once we
manage to fix splice() and actually provide perf-splice() you'd be able
to do zero-copy.
next prev parent reply other threads:[~2010-09-09 12:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-09 11:06 perf events over (net) console? Harald Gustafsson
2010-09-09 11:19 ` Peter Zijlstra
2010-09-09 11:29 ` Frederic Weisbecker
2010-09-09 11:35 ` Peter Zijlstra
2010-09-09 11:40 ` Frederic Weisbecker
2010-09-09 11:40 ` Ingo Molnar
2010-09-09 12:31 ` Harald Gustafsson
2010-09-09 12:47 ` Peter Zijlstra [this message]
2010-09-09 13:07 ` Ingo Molnar
2010-09-09 13:21 ` Frederic Weisbecker
2010-09-09 14:41 ` Arnaldo Carvalho de Melo
2010-09-09 17:42 ` Harald Gustafsson
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