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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>,
	Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Stephane Eranian <eranian@googlemail.com>,
	Eric Dumazet <dada1@cosmosbay.com>,
	Robert Richter <robert.richter@amd.com>,
	Arjan van de Veen <arjan@infradead.org>,
	Peter Anvin <hpa@zytor.com>,
	"David S. Miller" <davem@davemloft.net>,
	Maynard Johnson <mpjohn@us.ibm.com>,
	carll@us.ibm.com
Subject: Re: Performance counter API review was [patch] Performance Counters for Linux, v3
Date: Wed, 04 Feb 2009 11:51:44 +0100	[thread overview]
Message-ID: <1233744704.5076.4.camel@laptop> (raw)
In-Reply-To: <18825.29238.559809.341658@cargo.ozlabs.ibm.com>

On Wed, 2009-02-04 at 21:47 +1100, Paul Mackerras wrote:
> Peter Zijlstra writes:
> 
> > How is smp_call_function() going to help here? You still need to pull
> > all that data through that one FD. That's a cacheline bounce fest.
> 
> Well, let's put this into perspective.  We would be collecting 8 bytes
> of data from each CPU.  Hardly a "cacheline bounce fest". :)

Ah, I was thinking more of the event triggered profiling, like NMI time,
cachemiss or pagefault profiling.

In those cases you'd get a continuous stream of data for each cpu, at
possibly quite high speeds.


      reply	other threads:[~2009-02-04 10:52 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-11 15:52 [patch] Performance Counters for Linux, v3 Ingo Molnar
2008-12-11 18:02 ` Vince Weaver
2008-12-12  8:25   ` Peter Zijlstra
2008-12-12  8:35     ` stephane eranian
2008-12-12  8:51       ` Peter Zijlstra
2008-12-12  9:00         ` Peter Zijlstra
2008-12-12  9:07           ` Ingo Molnar
2008-12-12  8:59     ` stephane eranian
2008-12-12  9:23       ` Peter Zijlstra
2008-12-12 10:21         ` Robert Richter
2008-12-12 10:59           ` Christoph Hellwig
2008-12-12 11:35             ` Robert Richter
2008-12-12 16:45         ` Chris Friesen
2008-12-12 17:42         ` stephane eranian
2008-12-12 18:01           ` stephane eranian
2008-12-12 19:45             ` Chris Friesen
2008-12-15 14:50               ` stephane eranian
2008-12-15 22:32                 ` Chris Friesen
2008-12-17  7:45                   ` stephane eranian
2008-12-14 23:13             ` Ingo Molnar
2008-12-15  0:37               ` Paul Mackerras
2008-12-15 12:58                 ` stephane eranian
2008-12-15 14:42                 ` stephane eranian
2008-12-15 20:58               ` stephane eranian
2008-12-15 22:53               ` Paul Mackerras
2008-12-13 11:17           ` Peter Zijlstra
2008-12-13 13:48             ` Henrique de Moraes Holschuh
2008-12-13 17:44             ` stephane eranian
2008-12-14  1:02             ` Paul Mackerras
2008-12-14 22:37               ` Ingo Molnar
2008-12-15  0:50                 ` Paul Mackerras
2008-12-15 13:02                   ` stephane eranian
2008-12-12 17:03     ` Samuel Thibault
2008-12-12 17:11       ` Peter Zijlstra
2008-12-12 18:18     ` Vince Weaver
2008-12-11 18:35 ` Andrew Morton
2008-12-12  6:22   ` Ingo Molnar
2008-12-11 19:11 ` Tony Luck
2008-12-11 19:34   ` Ingo Molnar
2008-12-12  8:29     ` Peter Zijlstra
2008-12-12  8:54       ` Ingo Molnar
2008-12-12 13:42       ` Andi Kleen
2008-12-14 14:51 ` Performance counter API review was " Andi Kleen
2009-02-02 20:03   ` Corey Ashford
2009-02-02 20:33     ` Peter Zijlstra
2009-02-03 16:53       ` Maynard Johnson
2009-02-04  2:18       ` Paul Mackerras
2009-02-04  2:32         ` Nathan Lynch
2009-02-04  8:45         ` Peter Zijlstra
2009-02-04 10:47           ` Paul Mackerras
2009-02-04 10:51             ` Peter Zijlstra [this message]

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