Bug 42612 - Oprofile's IBS gathers no samples after suspend to RAM
Summary: Oprofile's IBS gathers no samples after suspend to RAM
Status: RESOLVED OBSOLETE
Alias: None
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64 (show other bugs)
Hardware: All Linux
: P1 low
Assignee: platform_x86_64@kernel-bugs.osdl.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-01-19 19:08 UTC by Michal Vaner
Modified: 2022-01-06 18:26 UTC (History)
3 users (show)

See Also:
Kernel Version: 3.2.1 gentoo
Subsystem:
Regression: Yes
Bisected commit-id:


Attachments
/proc/cpuinfo (5.42 KB, text/plain)
2012-01-19 19:08 UTC, Michal Vaner
Details

Description Michal Vaner 2012-01-19 19:08:49 UTC
Created attachment 72132 [details]
/proc/cpuinfo

Hello

If I boot my machine fresh and start oprofile, for example like:

opcontrol --setup -e IBS_OP_ALL:50000:0x00
opcontrol --start

everything works (oprofiled shows up in top with 1-2% CPU usage, opreport produces some meaningful output).

If I do the same after suspend to RAM and resume, it doesn't complain about anything, but produces no samples ("error: no sample files found: profile specification too strict ?") and doesn't eat any CPU. New reboot or suspend to disk and resume makes it work again (I'm inserting the oprofile module anew each time, not keeping it in for the suspend).

It works OK with 3.1.9. It works with the performance counters even after the suspend to RAM on 3.2.1.

My guess is that the suspend to RAM leaves the CPU in some different state than it was before the suspend and the interrupts which should be triggered by the IBS are not fired.

Which other information might be helpful?

Thank you
Comment 1 Borislav Petkov 2022-01-06 18:26:21 UTC
This one looks forgotten and oprofile is gone since v5.12 so lemme close...

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