Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 21 Jun 2023 12:31:45 -0700 | Subject | Re: [PATCHSET v1 wq/for-6.5] workqueue: Improve unbound workqueue execution locality |
| |
On Wed, 21 Jun 2023 at 12:16, Tejun Heo <tj@kernel.org> wrote: > > I find that perplexing given that switching to a per-cpu workqueue remedies > the situation quite a bit, which is how this patchset came to be. #3 is the > same as per-cpu workqueue, so if you're seeing noticeably different > performance numbers between #3 and per-cpu workqueue, there's something > wrong with either the code or test setup.
Or maybe there's some silly thinko in the wq code that is hidden by the percpu code.
For example, WQ_UNBOUND triggers a lot of other overhead at least on wq allocation and free. Maybe some of that stuff then indirectly affects workqueue execution even when strict cpu affinity is set.
Pin-Yen Li - can you do a system-wide profile of the two cases (the percpu case vs the "strict cpu affinity" one), to see if something stands out?
Linus
| |