Minutes of 8/25/05 meeting

[Jim Keniston <jkenisto at us dot ibm dot com>]

A week late.  Sorry.

Minutes of SystemTap Conference Call, August 25, 2005

Participants:
IBM:
	Vara Prasad (varap@us.ibm.com -- Beaverton)
	Jim Keniston (jkenisto@us.ibm.com -- Beaverton)
	Hien Nguyen (nguyhien@us.ibm.com -- Beaverton)
	Kevin Stafford (kevinrs@us.ibm.com -- Beaverton)
	Ananth Mavinakayanahalli (amavin@redhat.com, ananth@in.ibm.com --
Boston)
	Prasanna Panchamukhi (prasanna@in.ibm.com -- Bangalore)
	Maneesh Soni (maneesh@in.ibm.com -- Bangalore)
Red Hat:
	Elena Zannoni (ezannoni@redhat.com -- Boston)
	Frank Eigler (fche@redhat.com -- Toronto)
	Graydon Hoare (graydon@redhat.com)
Intel:
	Charles Spirakis (charles.spirakis@intel.com)
	Josh Stone

Actions Required (ARs):
>From 5/19/05:
19. Vara: Collect sample kprobes modules and post them to the
SystemTap web site.

22. Rusty: Look into x86_64 limitation re: temporary disarming of
reentrant probes.

23. Jim, Martin: Ensure that the runtime's stack-trace feature works
appropriately when there are return probes in the call stack.
[Update: Martin is working on this.  Jim will prototype an improvement
whereby the saved IP is updated before the handler is called.]

>From 6/9/05:
26. Rusty/Brad: Forward email address of Intel test person to Jay
Turner.  [Update: As of 7/7/05, Brad hasn't done this.  Did Rusty?]

>From 6/23/05:
30. Rusty: Review Will's rendition of Rusty's test that exercises
probes on a wide variety of instruction types.  [Update: As of 7/7/05,
Will still needs to hear back from Rusty.]

>From 7/7/05:
39. Ananth: Summarize the status of the ppc64 runtime port for Martin.
[Update 8/17/05: Jose Santos of the IBM pSeries performance team will
complete the port.]

>From 7/28/05:
41. Anil: Post a summary of known djprobes implementation issues.

>From 8/4/05:
43. Prasanna: Post work on user-space probes.  [Update: Design is
under review at IBM.  This is deferred until after current SystemTap
test/debug push.]

>From 8/11/05:
44. Tom: Automate relayfs tests and post them to mailing list.
[Update: In progress]

>From 8/18/05:
47. Elena: Report on availability of tech writer(s) at Red Hat to
help with user documentation.  [DONE: Nothing promising.  See #54.]

48. Elena, Vara: Manage planning of next face-to-face meeting.

49. Graydon, Frank: Publish an update to their translator feature
list of 8/4/05. [DONE 8/25/05]

50. Jim: Characterize the problem(s) we've seen when probing
schedule().  [Update 8/25/05: One problem was a translator bug
regarding return probes; this is fixed.  There's also an apparent
kprobes bug, bugzilla #1229.  IBM is investigating.]

53. Anil: Test RCU-based SMP scalability feature on ia64.

>From 8/25/05:
54. Vara: Report on availability of tech writer(s) at IBM to help
with user documentation.

55. Elena: Investigate approaches to making the full SystemTap bug
list available to SystemTap developers outside Red Hat.

What's the best way to report bugs against SystemTap?  One bugzilla
entry per bug.

On which releases should we be testing SystemTap, at least for now?
RHEL4 U2?  Yes.  Fedora?  No.

This morning, Graydon published an update to the translator's
"This works; this doesn't" list.

Apparently, bug reports against SystemTap may or may not be visible
outside Red Hat, depending on how they are submitted.  Elena will
investigate approaches to making the full bug list available to
SystemTap developers outside Red Hat.

There was some discussion about running tests, and how to automate
the process.  The test suite used internally by Red Hat for testing
releases is turn-key; other tests are more manual in nature.  Red Hat
is open to other folks automating the tests in CVS.  The translator
test suite in src/testsuite can be run using "make check" in src.
Frank suggested that, given the current size of the test suites,
test automation should take a back seat to test development.

User documentation was discussed.  Currently, the best sources of
how-to information are the stap(1) man page, the test suites
(src/testsuite/*ok/* and tests/testsuite), and bugzilla.  End users
will probably need more info.  Availablilty of tech writers at
Red Hat is currently spotty, reports Elena.  Vara will investigate
tech writer availability at IBM.

How can folks outside Red Hat best support testing?  Use SystemTap
to create real-world instrumentation, and report any problems you see.

Two kprobes bugs (bugzilla #1229 and #1234) are high priority.  IBM
is working on them.