I am noticing the cpufreq_driver_lock is quite hot. On an idle 512 system perf shows me most of the system time is spent on this lock. This is quite significant as top shows 5% of time in system time. My solution was to first convert the lock to a rwlock and then to the rcu.
v2: Rebase v3: Read the RCU documentation instead of skimming it. Also I based on git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git pm+acpi-3.9-rc1 I assumed that was what you would prefer Rafael. v4: Removed an unnecessary syncronize_rcu(). Nathan Zimmer (2): cpufreq: Convert the cpufreq_driver_lock to a rwlock cpufreq: Convert the cpufreq_driver_lock to use the rcu drivers/cpufreq/cpufreq.c | 286 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 211 insertions(+), 75 deletions(-) -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
