On 09/25/2018 12:36 PM, Waiman Long wrote: > On 09/25/2018 12:31 PM, Peter Zijlstra wrote: >> Also, where is the performance benefit here. The normal lock_acquire >> path doesn't change gobal state (it will not see new lock ordering in >> 99%+ of the cases). >> >> Typically we only push the lock on the task local lock stack, compute >> the new hash, and do the hash lookup, find it already exists and return. >> >> So what is the expensive part, and can we do something about that? > I will need to do some experimentation to find out. Will update this > thread with my finding. >
I have sent out a patchset on improving lockdep performance that hopefully will help to alleviate the problems that I saw. I still have other ideas about further changes I want to investigate, but that will wait until I am done with the current lockdep patchset. -Longman
