Messages in this thread | | | Date | Tue, 2 Oct 2018 11:06:52 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 0/5] locking/lockdep: Improve lockdep performance |
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* Waiman Long <longman@redhat.com> wrote:
> Enabling CONFIG_LOCKDEP and other related debug options will greatly > reduce system performance. This patchset aims to reduce the performance > slowdown caused by the lockdep code. > > Patch 1 just removes an inline function that wasn't used. > > Patches 2 and 3 are minor twists to optimize the code. > > Patch 4 makes class->ops a per-cpu counter. > > Patch 5 moves the lock_release() call outside of a lock critical section. > > Parallel kernel compilation tests (make -j <#cpu>) were performed on > 2 different systems: > > 1) an 1-socket 22-core 44-thread Skylake system > 2) a 4-socket 72-core 144-thread Broadwell system > > The build times with pre-patch and post-patch debug kernels were: > > System Pre-patch Post-patch %Change > ------ --------- ---------- ------- > 1-socket 8m53.9s 8m41.2s -2.4% > 4-socket 7m27.0s 5m31.0s -26% > > I think it is the last 2 patches that yield most of the performance > improvement.
Impressive speedup!
Mind including the non-lockdep numbers as well, for reference?
Thanks,
Ingo
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