From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753993Ab1ALOmv (ORCPT <rfc822;w@1wt.eu>);
	Wed, 12 Jan 2011 09:42:51 -0500
Received: from mail-fx0-f46.google.com ([209.85.161.46]:47712 "EHLO
	mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752755Ab1ALOmt (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 12 Jan 2011 09:42:49 -0500
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=date:from:to:cc:subject:message-id:references:mime-version
         :content-type:content-disposition:in-reply-to:user-agent;
        b=wOFW9+UWsKaxTuHocqolAfh+hYGmHO0MXAzEBjKewTntGtBE04SU+W6tCEqril8HC3
         J3qjxxfJ2pbGP2RACp3KyS4KJAFB66jTzc3A7acfRMmOTHZmBuqM2Bc6rf9W2XEU3sit
         X3RA4ScPnPDuS2Zdzx9ioI2RgnfcmpCQkGYRg=
Date: Wed, 12 Jan 2011 15:42:43 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Kirill Smelkov <kirr@mns.spb.ru>, linux-kernel@vger.kernel.org,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Ingo Molnar <mingo@elte.hu>, Mike Galbraith <efault@gmx.de>,
        Paul Mackerras <paulus@samba.org>,
        Stephane Eranian <eranian@google.com>,
        Tom Zanussi <tzanussi@gmail.com>
Subject: Re: Q: perf log mode?
Message-ID: <20110112144240.GA1755@nowhere>
References: <20110112140613.GA11698@tugrik.mns.mnsspb.ru>
 <1294841288.19601.49.camel@laptop>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1294841288.19601.49.camel@laptop>
User-Agent: Mutt/1.5.20 (2009-06-14)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Jan 12, 2011 at 03:08:08PM +0100, Peter Zijlstra wrote:
> On Wed, 2011-01-12 at 17:06 +0300, Kirill Smelkov wrote:
> > I'm trying to use perf together with e.g. kprobes as a tool to show what
> > is happening with my system in "live-log" mode. The problem is, for
> > seldom events, actual info output is largely delayed because perf reads
> > sample data in whole pages. Could something be done with it or am I'm
> > missing something? Here is detailed description: 
> 
> perf_event_attr = {
> 	.watermark = 0,
> 	.wakeup_events = 1,
> };


Which is perhaps something we want as a default when perf record -c 1
and the output is the pipe mode.