Revision 7f453c24b95a085fc7bd35d53b33abc4dc5a048b authored by Peter Zijlstra on 21 July 2009, 11:19:40 UTC, committed by Peter Zijlstra on 22 July 2009, 16:05:56 UTC
Anton noted that for inherited counters the counter-id as provided by PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID because each inherited counter gets its own id. His suggestion was to always return the parent counter id, since that is the primary counter id as exposed. However, these inherited counters have a unique identifier so that events like PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which counter gets modified, which is important when trying to normalize the sample streams. This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD, which is more useful anyway, since changing periods became a lot more common than initially thought -- rendering PERF_EVENT_PERIOD the less useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate value, since it reports the value used to trigger the overflow, whereas PERF_EVENT_PERIOD simply reports the requested period changed, which might only take effect on the next cycle). This still leaves us PERF_EVENT_THROTTLE to consider, but since that _should_ be a rare occurrence, and linking it to a primary id is the most useful bit to diagnose the problem, we introduce a PERF_SAMPLE_STREAM_ID, for those few cases where the full reconstruction is important. [Does change the ABI a little, but I see no other way out] Suggested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1248095846.15751.8781.camel@twins>
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REPORTING-BUGS
[Some of this is taken from Frohwalt Egerer's original linux-kernel FAQ]
What follows is a suggested procedure for reporting Linux bugs. You
aren't obliged to use the bug reporting format, it is provided as a guide
to the kind of information that can be useful to developers - no more.
If the failure includes an "OOPS:" type message in your log or on
screen please read "Documentation/oops-tracing.txt" before posting your
bug report. This explains what you should do with the "Oops" information
to make it useful to the recipient.
Send the output to the maintainer of the kernel area that seems to
be involved with the problem, and cc the relevant mailing list. Don't
worry too much about getting the wrong person. If you are unsure send it
to the person responsible for the code relevant to what you were doing.
If it occurs repeatably try and describe how to recreate it. That is
worth even more than the oops itself. The list of maintainers and
mailing lists is in the MAINTAINERS file in this directory.
If it is a security bug, please copy the Security Contact listed
in the MAINTAINERS file. They can help coordinate bugfix and disclosure.
See Documentation/SecurityBugs for more information.
If you are totally stumped as to whom to send the report, send it to
linux-kernel@vger.kernel.org. (For more information on the linux-kernel
mailing list see http://www.tux.org/lkml/).
This is a suggested format for a bug report sent to the Linux kernel mailing
list. Having a standardized bug report form makes it easier for you not to
overlook things, and easier for the developers to find the pieces of
information they're really interested in. Don't feel you have to follow it.
First run the ver_linux script included as scripts/ver_linux, which
reports the version of some important subsystems. Run this script with
the command "sh scripts/ver_linux".
Use that information to fill in all fields of the bug report form, and
post it to the mailing list with a subject of "PROBLEM: <one line
summary from [1.]>" for easy identification by the developers.
[1.] One line summary of the problem:
[2.] Full description of the problem/report:
[3.] Keywords (i.e., modules, networking, kernel):
[4.] Kernel information
[4.1.] Kernel version (from /proc/version):
[4.2.] Kernel .config file:
[5.] Most recent kernel version which did not have the bug:
[6.] Output of Oops.. message (if applicable) with symbolic information
resolved (see Documentation/oops-tracing.txt)
[7.] A small shell script or example program which triggers the
problem (if possible)
[8.] Environment
[8.1.] Software (add the output of the ver_linux script here)
[8.2.] Processor information (from /proc/cpuinfo):
[8.3.] Module information (from /proc/modules):
[8.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem)
[8.5.] PCI information ('lspci -vvv' as root)
[8.6.] SCSI information (from /proc/scsi/scsi)
[8.7.] Other information that might be relevant to the problem
(please look in /proc and include all information that you
think to be relevant):
[X.] Other notes, patches, fixes, workarounds:
Thank you
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