On Tuesday, July 24, 2018 8:26:03 PM CEST Waiman Long wrote: > v2: > - Remove the retry loop in the store method. > > This patchset works around a circular lock dependency issue in the > cpufreq driver reported by lockdep. The two locks involved are the > cpu_hotplup_lock and the reference count of a sysfs file. > > The cpufreq_register_driver() function uses the lock sequence: > > cpus_read_lock --> kn->count > > Whereas the cpufreq sysfs store method uses the sequence: > > kn->count --> cpus_read_lock > > This is not really an issue as a shared lock is used on the > cpu_hotplup_lock. However, the lockdep code isn't able to handle > shared locking. So one way to work around this is to define a > cpus_read_trylock() function and uses it in the store method instead. > > Waiman Long (2): > cpu/hotplug: Add a cpus_read_trylock() function > cpufreq: Fix a circular lock dependency problem > > drivers/cpufreq/cpufreq.c | 7 ++++++- > include/linux/cpu.h | 2 ++ > kernel/cpu.c | 6 ++++++ > 3 files changed, 14 insertions(+), 1 deletion(-) > >
I'm queuing up this series for 4.19. If anyone has any concerns regarding it, please let me know. Thanks, Rafael
