linux/drivers/cpufreq
Ashok Raj 90d45d17f3 [PATCH] cpu hotplug: fix locking in cpufreq drivers
When calling target drivers to set frequency, we take cpucontrol lock.
When we modified the code to accomodate CPU hotplug, there was an attempt
to take a double lock of cpucontrol leading to a deadlock.  Since the
current thread context is already holding the cpucontrol lock, we dont need
to make another attempt to acquire it.

Now we leave a trace in current->flags indicating current thread already is
under cpucontrol lock held, so we dont attempt to do this another time.

Thanks to Andrew Morton for the beating:-)

From: Brice Goglin <Brice.Goglin@ens-lyon.org>

  Build fix

(akpm: this patch is still unpleasant.  Ashok continues to look for a cleaner
solution, doesn't he?  ;))

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:50 -08:00
..
Kconfig [CPUFREQ] Conservative cpufreq governer 2005-05-31 19:03:47 -07:00
Makefile [CPUFREQ] Conservative cpufreq governer 2005-05-31 19:03:47 -07:00
cpufreq.c [PATCH] cpu hotplug: fix locking in cpufreq drivers 2005-11-09 07:55:50 -08:00
cpufreq_conservative.c [PATCH] cpufreq: SMP fix for conservative governor 2005-10-27 16:29:24 -07:00
cpufreq_ondemand.c [CPUFREQ] Avoid the ondemand cpufreq governor to use a too high frequency for stats. 2005-09-20 12:39:35 -07:00
cpufreq_performance.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cpufreq_powersave.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cpufreq_stats.c Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq 2005-11-07 13:28:20 -08:00
cpufreq_userspace.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
freq_table.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00