From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 39595 invoked by alias); 8 Jul 2015 08:08:34 -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 38462 invoked by uid 48); 8 Jul 2015 08:08:30 -0000 From: "izi.an.contact at gmail dot com" To: systemtap@sourceware.org Subject: [Bug runtime/18642] New: Probes not always invoked when probed functions are called Date: Wed, 08 Jul 2015 08:08:00 -0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: runtime X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: izi.an.contact at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone attachments.created Message-ID: 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: 2015-q3/txt/msg00017.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=18642 Bug ID: 18642 Summary: Probes not always invoked when probed functions are called Product: systemtap Version: unspecified Status: NEW Severity: normal Priority: P2 Component: runtime Assignee: systemtap at sourceware dot org Reporter: izi.an.contact at gmail dot com Target Milestone: --- Created attachment 8421 --> https://sourceware.org/bugzilla/attachment.cgi?id=8421&action=edit stap-report output Systemtap probes are invoked only some of the time when the probed function is called. This happens in two scenarios which may or may not be related: 1. Scenario I: System calls such as read, write or bind using probes syscall.* (e.g.: syscall.read, syscall.write, syscall.bind) are not called consistently. In contrast, when using process.syscall probe, the probes are called consistently when the probed functions are called. We can't understand the discrepancy between the probe types behavior. 2. Scenario II: Probe for process creation using probe kernel.function("sys_execve") and user space probes for the created process (and its subprocesses) are not called consistently. In our system the created process is usually bash, and the user space probes on bash - probe process("/bin/bash").function("pre_process_line") probe process("/bin/bash").function("read_command") are not invoked either when process creation probe isn't invoked. -- It is worth mentioning that in these scenarios we run systemtap over an lxc container and all the relevant processes run in this container. Attached is the output from stap-report. We run systemtap 2.7 over ubuntu 14.04.2 (kernel 3.13.0-24-generic). -- You are receiving this mail because: You are the assignee for the bug.