From: "izi.an.contact at gmail dot com" <sourceware-bugzilla@sourceware.org>
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 [thread overview]
Message-ID: <bug-18642-6586@http.sourceware.org/bugzilla/> (raw)
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.
next reply other threads:[~2015-07-08 8:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-08 8:08 izi.an.contact at gmail dot com [this message]
2015-07-08 14:12 ` [Bug runtime/18642] " dsmith at redhat dot com
2016-05-24 15:29 ` fche at redhat dot com
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bug-18642-6586@http.sourceware.org/bugzilla/ \
--to=sourceware-bugzilla@sourceware.org \
--cc=systemtap@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).