On 5 November 2014 20:23, Prarit Bhargava <pra...@redhat.com> wrote: > The usage_count value can be modified from several cpus concurrently if > !CPUFREQ_HAVE_GOVERNOR_PER_POLICY. This leads to a variety of panics in > which the usage_count is negative or exceeds the number of cpus in the > system. It must be switched to atomic_t and protected with a mutex to make > sure > that future read/writes obtain the correct data.
I think it would be best to serialize calls to ->governor() with some locking in place instead of adding per-variable locks. There can be other points of contention as well. I have done something similar in the solution I tried. Can pick some of those patches. -- 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/
