From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8413 invoked by alias); 20 Nov 2014 07:49:02 -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 8384 invoked by uid 48); 20 Nov 2014 07:48:57 -0000 From: "peter at peca dot dk" To: systemtap@sourceware.org Subject: [Bug uprobes/17623] Sometimes probes fail to fire events when running against a multi-threaded application Date: Thu, 20 Nov 2014 07:49:00 -0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: uprobes X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: peter at peca dot dk X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2014-q4/txt/msg00166.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=17623 --- Comment #3 from Peter Allin --- (In reply to Frank Ch. Eigler from comment #2) > Peter, have you by any chance tried out "perf probe" against your > original binary, to see if this is may be a kernel-side rather > than stap-side problem? I have just tried it, and am somewhat confused by the results. Here is what I did: - perf probe -x testprog func1 - perf probe -x testprog func2 - Start testprog in another terminal - perf stat -e probe_testprog:func1 -e probe_testprog:func2 -a sleep 1 I ran the last command in a loop for 1000 times. It always shows counts for both probe points, but the counts are not equal. So it seems that SystemTap will either work perfectly or loose all events from one of the probes, while perf is always missing some events but not all. Do you think this is caused by two separate problems, or are both pointing towards a kernel problem? -- You are receiving this mail because: You are the assignee for the bug.