http://bugzilla.kernel.org/show_bug.cgi?id=13493
--- Comment #6 from Márton Németh <[email protected]> 2009-06-12 04:19:58 --- Created an attachment (id=21864) --> (http://bugzilla.kernel.org/attachment.cgi?id=21864) git bisect log I bisected this problem on an EeePC 901. The result is: b14893a62c73af0eca414cfed505b8c09efc613c is first bad commit commit b14893a62c73af0eca414cfed505b8c09efc613c Author: Mathieu Desnoyers <[email protected]> Date: Sun May 17 10:30:45 2009 -0400 [CPUFREQ] fix timer teardown in ondemand governor * Rafael J. Wysocki ([email protected]) wrote: > This message has been generated automatically as a part of a report > of regressions introduced between 2.6.28 and 2.6.29. > > The following bug entry is on the current list of known regressions > introduced between 2.6.28 and 2.6.29. Please verify if it still should > be listed and let me know (either way). > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13186 > Subject : cpufreq timer teardown problem > Submitter : Mathieu Desnoyers <[email protected]> > Date : 2009-04-23 14:00 (24 days old) > References : http://marc.info/?l=linux-kernel&m=124049523515036&w=4 > Handled-By : Mathieu Desnoyers <[email protected]> > Patch : http://patchwork.kernel.org/patch/19754/ > http://patchwork.kernel.org/patch/19753/ > (updated changelog) cpufreq fix timer teardown in ondemand governor The problem is that dbs_timer_exit() uses cancel_delayed_work() when it should use cancel_delayed_work_sync(). cancel_delayed_work() does not wait for the workqueue handler to exit. The ondemand governor does not seem to be affected because the "if (!dbs_info->enable)" check at the beginning of the workqueue handler returns immediately without rescheduling the work. The conservative governor in 2.6.30-rc has the same check as the ondemand governor, which makes things usually run smoothly. However, if the governor is quickly stopped and then started, this could lead to the following race : dbs_enable could be reenabled and multiple do_dbs_timer handlers would run. This is why a synchronized teardown is required. The following patch applies to, at least, 2.6.28.x, 2.6.29.1, 2.6.30-rc2. Depends on patch cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call Signed-off-by: Mathieu Desnoyers <[email protected]> CC: Andrew Morton <[email protected]> CC: [email protected] CC: [email protected] CC: [email protected] CC: Ingo Molnar <[email protected]> CC: [email protected] CC: Ben Slusky <[email protected]> Signed-off-by: Dave Jones <[email protected]> :040000 040000 d7fb0f04e2d13be36ff8a5fba2e6bbcff4406996 482e48e8a15065bf48e28a98db06433ced382551 M drivers -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ acpi-bugzilla mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
