From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2493 invoked by alias); 9 Oct 2009 17:08:17 -0000 Received: (qmail 2484 invoked by uid 22791); 9 Oct 2009 17:08:16 -0000 X-SWARE-Spam-Status: No, hits=-2.2 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from e28smtp01.in.ibm.com (HELO e28smtp01.in.ibm.com) (59.145.155.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 09 Oct 2009 17:08:10 +0000 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by e28smtp01.in.ibm.com (8.14.3/8.13.1) with ESMTP id n99H87DV002856 for ; Fri, 9 Oct 2009 22:38:07 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n99H86Su2924642 for ; Fri, 9 Oct 2009 22:38:06 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id n99H86TH008902 for ; Fri, 9 Oct 2009 22:38:06 +0530 Received: from localhost ([9.77.196.232]) by d28av01.in.ibm.com (8.14.3/8.13.1/NCO v10.0 AVin) with ESMTP id n99H86sN008883; Fri, 9 Oct 2009 22:38:06 +0530 Date: Fri, 09 Oct 2009 17:08:00 -0000 From: Rajasekhar Duddu To: "Frank Ch. Eigler" Cc: systemtap@sources.redhat.com Subject: Re: [PATCH v3] Tracepoint Tapset for Memory Subsystem Message-ID: <20091009170805.GA7769@rajduddu> References: <4AB90BE0.4030405@redhat.com> <4AB94A1B.4090801@redhat.com> <20090924180817.GA9698@rajduddu> <4ABD3B2B.4020107@redhat.com> <20090930101156.GA3792@rajduddu> <20091002151344.GA9516@rajduddu> <20091007130728.GA6574@rajduddu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2009-q4/txt/msg00108.txt.bz2 On Wed, Oct 07, 2009 at 03:51:07PM -0400, Frank Ch. Eigler wrote: > Rajasekhar Duddu writes: > > > [...] > >> Nice. I thought that the raison d'etre for these aliases was to > >> abstract the presence or absence of tracepoints, so is there no > >> fallback kprobe available? Something like this: > >> > > Fallback kprobe is not available for other memory functions because > > the variables exported by them are will be modified. > > Could you elaborate? Do you mean that the same values may not be > available from a kprobe context? > > Hi Frank, Yes, the same values may not be available from a kprobe context, for example if we take "ret" variable as it is populated mid-way in the function and it is also the return value of a function which can be captured only by a return probe. But by a return probe we cannot capture the formal parameters of the memory function. Thanks -- Rajasekhar Duddu (rajduddu@linux.vnet.ibm.com), Linux on System z - CSVT, IBM LTC, Bangalore.