From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11607 invoked by alias); 16 Nov 2007 19:13:03 -0000 Received: (qmail 11590 invoked by uid 22791); 16 Nov 2007 19:13:01 -0000 X-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00,DK_POLICY_SIGNSOME,FORGED_RCVD_HELO,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 16 Nov 2007 19:12:58 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.1) with ESMTP id lAGJCuhl006171; Fri, 16 Nov 2007 14:12:56 -0500 Received: from pobox-2.corp.redhat.com (pobox-2.corp.redhat.com [10.11.255.15]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lAGJCuMm005657; Fri, 16 Nov 2007 14:12:56 -0500 Received: from localhost.localdomain (dhcp-170.hsv.redhat.com [172.16.17.170]) by pobox-2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lAGJCtON008327; Fri, 16 Nov 2007 14:12:55 -0500 Message-ID: <473DEBB7.40607@redhat.com> Date: Fri, 16 Nov 2007 19:13:00 -0000 From: David Smith User-Agent: Thunderbird 2.0.0.5 (X11/20070727) MIME-Version: 1.0 To: Mathieu Desnoyers CC: ltt-dev@shafik.org, Systemtap List Subject: Re: patches to actually use markers? References: <472633E3.1050507@redhat.com> <20071029220454.GB4233@Krystal> <4728AD5F.1010604@redhat.com> In-Reply-To: <4728AD5F.1010604@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit 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: 2007-q4/txt/msg00350.txt.bz2 David Smith wrote: > Mathieu Desnoyers wrote: >> * David Smith (dsmith@redhat.com) wrote: >>> Mathieu, >>> >>> Now that the markers facility itself has made it in the kernel, do >>> you have plans on trying to send patches that actually use markers to >>> lkml? >>> >>> For systemtap's use, we'd like to get some actual markers in the >>> upstream kernel. Off the top of my head, we might start with adding >>> markers to system calls (sys_*) that contain the system call's >>> argument(s). >>> >> >> Hi David, >> >> Yes, we have something similar in LTTng, we instrument many widely used >> system calls to get the detailed arguments. ... >> It's a good thing that we start having a discussion about these marker >> sites at this point. >> >> Mathieu I've been looking at your system call tracing patches. (I've tried running lttv itself without much luck, but it doesn't really matter for the sake of this discussion.) I like the way you use the existing system call tracing points. So we're on the same page, here are the markers I'm seeing in arch/x86/kernel/ptrace32.c after applying patch-2.6.24-rc2-lttng-0.10-pre23.tar.bz2: trace_mark(kernel_arch_syscall_entry, "syscall_id %d ip #p%ld", (int)regs->orig_eax, instruction_pointer(regs)); trace_mark(kernel_arch_syscall_exit, MARK_NOARGS); For systemtap use, we'd like to have more information than that. On syscall entry, we'd like be able to get the arguments, On syscall exit, we'd like the to be able to get the return value. In fact, the easiest thing would be to supply the same information that audit_syscall_entry() and audit_syscall_exit() need. Since I'll bet you've already considered this, I'd like to know why you decided to go a different way. Thanks. -- David Smith dsmith@redhat.com Red Hat http://www.redhat.com 256.217.0141 (direct) 256.837.0057 (fax)