From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23476 invoked by alias); 26 Oct 2013 11:16:41 -0000 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 Received: (qmail 23463 invoked by uid 89); 26 Oct 2013 11:16:41 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.1 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sat, 26 Oct 2013 11:16:40 +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 r9QBG7LZ006943 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Sat, 26 Oct 2013 07:16:07 -0400 Received: from fche.csb (vpn-54-115.rdu2.redhat.com [10.10.54.115]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r9QBG6De006531; Sat, 26 Oct 2013 07:16:07 -0400 Received: by fche.csb (Postfix, from userid 2569) id 16D975813D; Sat, 26 Oct 2013 07:16:06 -0400 (EDT) To: Pekka Enberg Cc: Hemant Kumar , LKML , Srikar Dronamraju , Peter Zijlstra , Oleg Nesterov , hegdevasant@linux.vnet.ibm.com, Ingo Molnar , anton@redhat.com, systemtap@sourceware.org, Namhyung Kim , Masami Hiramatsu , aravinda@linux.vnet.ibm.com Subject: Re: [PATCH v4 2/3] Support for perf to probe into SDT markers: References: <20131023044511.1886.82571.stgit@hemant-fedora> <20131023050502.1886.15779.stgit@hemant-fedora> From: fche@redhat.com (Frank Ch. Eigler) Date: Sat, 26 Oct 2013 11:16:00 -0000 In-Reply-To: (Pekka Enberg's message of "Fri, 25 Oct 2013 14:38:17 +0200") Message-ID: User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2013-q4/txt/msg00103.txt.bz2 Pekka Enberg writes: > Is there a technical reason why 'perf list' could not show all the > available SDT markers on a system and that the 'mark to event' > mapping cannot happen automatically? [...] A quick experiment with: find `echo $PATH | tr : ' '` -type f -perm -555 | xargs readelf -n 2>/dev/null | grep STAP 2>/dev/null suggests reasonable performance for my F19 workstation (a second or two over ~6000 executables), once all the ELF content is in the block cache. According to a stap eventcount.stp run, that required about 50000 syscall.read events. Note that a $PATH search excludes shared libraries, which can also carry markers. Adding /usr/lib* in more than doubles the work, then there's /usr/libexec etc. - FChE