Bug 495560

Summary:	systemtap needs trace headers in kernel-devel to let traceprobes work
Product:	Red Hat Enterprise MRG	Reporter:	Arnaldo Carvalho de Melo <acme>
Component:	realtime-kernel	Assignee:	Clark Williams <williams>
Status:	CLOSED WONTFIX	QA Contact:	David Sommerseth <davids>
Severity:	medium	Docs Contact:
Priority:	low
Version:	Development	CC:	bhu, fche, lgoncalv, ovasik, wcohen
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	494950	Environment:
Last Closed:	2011-09-28 16:44:56 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	494950
Bug Blocks:	329781

Description Arnaldo Carvalho de Melo 2009-04-13 19:55:20 UTC

+++ This bug was initially created as a clone of Bug #494950 +++

Created an attachment (id=338784)
patch to add trace subdir to kernel-devel package

Description of problem:
AS part of my writing a script to emulate dropwatch via systemtap, I noted that I was not able to use kernel.trace probes or the stap -L option to list available probes.  stap always returned a NULL search result (indicating no tracepoints available).  The problem turns out to be that the kernel-devel package fails to include the include/trace subdirectory, so stap can't find any included probes.  We need to include this to allow systemtap to properly use tracepoints in 5.4



How reproducible:
Always

Steps to Reproduce:
1. run stap -L 'kernel.trace("*")'

  
Actual results:
semantic error: no match while resolving probe point kernel.trace("*")

Expected results:
list of available tracepoints in the kernel

Additional info:

--- Additional comment from pm-rhel on 2009-04-08 15:39:12 EDT ---

This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 1 Frank Ch. Eigler 2011-09-28 16:44:56 UTC

The stap code related to kernel tracepoints has learned to find tracepoint headers inside the source tree also.  It's not perfect, but is another way forward.