On 4 August 2014 17:55, Prarit Bhargava <pra...@redhat.com> wrote: > The issue is the collision between the setup & teardown of the policy's > governor > sysfs files. > > On creation the kernel does: > > down_write(&policy->rwsem) > mutex_lock(kernfs_mutex) <- note this is similar to the "old" sysfs_mutex. > > The opposite happens on a governor switch, specifically the existing > governor's > exit, and then we get a lockdep warning.
Okay, probably a bit more clarity is what I was looking for. Suppose we try to change governor, now tell me what will happen. > I tried to reproduce with the instructions but was unable to ... ut that was > on > Friday ;) and I'm going to try again this morning. I've also ping'd some of > the > engineers here in the office who are working on ARM to get access to a system > to > do further analysis and testing. You DON'T need an ARM for that, just try that on any x86 machine which has multiple groups of CPUs sharing clock line. Or in other terms there are multiple policy structures there.. You just need to enable the flag we were discussing about, it just decided the location where governor's directory will get created. Nothing else. -- 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/
