From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6279 invoked by alias); 21 Nov 2014 14:45:47 -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 6217 invoked by uid 48); 21 Nov 2014 14:45:41 -0000 From: "dsmith at redhat dot com" To: systemtap@sourceware.org Subject: [Bug uprobes/17623] Sometimes probes fail to fire events when running against a multi-threaded application Date: Fri, 21 Nov 2014 14:45:00 -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: dsmith at redhat dot com 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/msg00177.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=17623 --- Comment #7 from David Smith --- (In reply to Peter Allin from comment #6) > (In reply to David Smith from comment #5) > > On my F20 vm (3.16.3-200.fc20.x86_64), your test program and script worked > > fine (even at WAIT_US 1). What kernel are you running? > > That sounds promising :-) I am running a kernel supplied by the Ubuntu > project, they call it "3.13.0-24-generic #47-Ubuntu". I am working remotely > today, and won't risk loosing access to the server by messing a kernel > upgrade up (got to get that remote power switch configured..), but I'll > defintely try upgrading it on monday. > > > When you finally stopped systemtap, did it report any skipped probes? > > No I haven't seen any such reports. I stop it either by ctrl-c or by running > it under the "timeout" command. Could these ways of stopping it inhibit > messages about skipped probes? The skipped probes message would have come out at the end after either using ctrl-c or using the timeout command. > > Depending on what you get with test2.stp, can I ask you to try with HEAD > > systemtap and see what you get? > > The behavior is consistent with my version of the script. If I run the > testprogram with the -c option of stap, I gets equals counts. When I run the > test program in the background only "func1" is counted. (I don't know if > this could give any hints, if I switch the order of the probes in the .stp > file, it is "func2" that works). > > Given this result, whould it make sense to try out the HEAD systemtap? It might if you have the time. It will provide another data point to whether this is a kernel issue or a systemtap issue. -- You are receiving this mail because: You are the assignee for the bug.