Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756412Ab0KJPAd (ORCPT ); Wed, 10 Nov 2010 10:00:33 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:64304 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755533Ab0KJPAc (ORCPT ); Wed, 10 Nov 2010 10:00:32 -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=lAwfP/leTYxjZCPi/uLePwxZNQvEvVkS1NPV64wy0Mgv6IbpPwVAtCBQHpG6KfhrtL IQUeVJLKamGV7yF830V8AlfVGjmrU/7d1u9OM7vDbGaGJseulxA/N1k/eEg+dKztL0Jn JK50wzGOTQ3Pum7wfzwIoG9gKqIDvgruLhgk0= Date: Wed, 10 Nov 2010 16:00:25 +0100 From: Frederic Weisbecker To: Ingo Molnar Cc: Jiri Olsa , Christoph Hellwig , rostedt@goodmis.org, andi@firstfloor.org, lwoodman@redhat.com, linux-kernel@vger.kernel.org, Peter Zijlstra Subject: Re: [PATCH 1/2] tracing,mm - add kernel pagefault tracepoint for x86 & x86_64 Message-ID: <20101110150021.GA5750@nowhere> References: <1289390172-9730-1-git-send-email-jolsa@redhat.com> <1289390172-9730-2-git-send-email-jolsa@redhat.com> <20101110132954.GA2101@infradead.org> <20101110134436.GD1949@jolsa.brq.redhat.com> <20101110135244.GA31638@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101110135244.GA31638@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1505 Lines: 39 On Wed, Nov 10, 2010 at 02:52:44PM +0100, Ingo Molnar wrote: > > * Jiri Olsa wrote: > > > On Wed, Nov 10, 2010 at 08:29:54AM -0500, Christoph Hellwig wrote: > > > On Wed, Nov 10, 2010 at 12:56:11PM +0100, Jiri Olsa wrote: > > > > + TP_printk("task=%lx, address=%lx, regs=%lx", > > > > + (unsigned long)__entry->task, (unsigned long)__entry->address, > > > > + __entry->regs) > > > > > > How exactly do you use the information in this trace point? Especially > > > the undecoded pt_regs doesn't seem very useful to me at all. > > > > agreed, the registers pointer are not very useful in the trace file output, > > and could be taken away.. just wanted to be complete I guess > > > > but I believe they are useful when you register the mm_kernel_pagefault > > tracepoint and process the information by yourself > > That would be expressed in a better and more generic fashion via adding > PERF_SAMPLE_REGS to perf_event_sample_format, and add a ptregs dump in > kernel/perf_event.c, perf_output_sample(). That way any tracepoint can request a > (user-space)ptregs state snapshot, not just the pagefault ones. > > Thanks, > > Ingo We are going to have that with the dwarf based callchain patchset. I'm cooking this. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/