From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12638 invoked by alias); 28 Nov 2012 19:01:33 -0000 Received: (qmail 12609 invoked by uid 22791); 28 Nov 2012 19:01:31 -0000 X-SWARE-Spam-Status: No, hits=-6.5 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 28 Nov 2012 19:01:24 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id qASJ1KWl016196 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 28 Nov 2012 14:01:20 -0500 Received: from host2.jankratochvil.net (ovpn-116-104.ams2.redhat.com [10.36.116.104]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id qASJ1F9x009118 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 28 Nov 2012 14:01:18 -0500 Date: Wed, 28 Nov 2012 19:01:00 -0000 From: Jan Kratochvil To: Markus Metzger Cc: "Metzger, Markus T" , "gdb-patches@sourceware.org" , "palves@redhat.com" , "tromey@redhat.com" , "kettenis@gnu.org" Subject: Re: [patch v4 00/13] branch tracing support for Atom Message-ID: <20121128190113.GA20881@host2.jankratochvil.net> References: <1354013351-14791-1-git-send-email-markus.t.metzger@intel.com> <20121127131055.GB22431@host2.jankratochvil.net> <20121127143235.GA31270@host2.jankratochvil.net> <20121127153603.GA1899@host2.jankratochvil.net> <20121127162740.GA4512@host2.jankratochvil.net> <20121127175955.GA8901@host2.jankratochvil.net> <11AC197E-8662-45CB-9D99-355786849BD8@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <11AC197E-8662-45CB-9D99-355786849BD8@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2012-11/txt/msg00824.txt.bz2 On Tue, 27 Nov 2012 19:56:07 +0100, Markus Metzger wrote: > I hard-coded one page of trace (or, rather, perf_event) buffer per thread. > We could make this configurable. I have not done this, yet, since I wanted > to keep the patch series small and simple until I get feedback. Sorry for not reading the kernel arch code etc. for it but if the buffer is so small - mostly just catching the last jump to NULL, I would find better if kernel does not have to trap at all and saves just the last 4 or 16 jumps IIRC without any performance penalty, is there such an option? Sure some full buffer recording with virtual backtraces and reverse-* would be fine but that is probably out of the scope of this initial patchset. Thanks, Jan