Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 2 Jan 2023 17:09:46 +0100 | From | Michal Koutný <> | Subject | Re: [PATCH RFC 2/2] mm: kmem: add direct objcg pointer to task_struct |
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Hello.
On Thu, Dec 22, 2022 at 08:21:49AM -0800, Roman Gushchin <roman.gushchin@linux.dev> wrote: > Do you have any numbers to share?
The numbers are in bko#216038, let me explain them here a bit. I used the will-it-scale benchmark that repeatedly locks/unlocks a file and runs in parallel.
The final numbers were: sample metric δ δ_cg no accounting implemented 32307750 0 % accounting in cg 2.49577e+07 -23 % 0 % accounting in cg + cache 2.51642e+07 -22 % +1 %
Hence my result was only 1% improvement.
(But it was a very simple try, not delving into any of the CPU cache statistics.)
Question: Were your measurements multi-threaded?
> 1) some people periodically complain that accounted allocations are slow > in comparison to non-accounted and slower than they were with page-based > accounting,
My result above would not likely satisfy those complainers I know about. But if your additional changes are better the additional code complexity may be justified in the end.
> Btw, I'm working on a patch 3 for this series, which in early tests brings > additional ~25% improvement in my benchmark, hopefully will post it soon as > a part of v1.
Please send it with more details about your benchmark to put the numbers into context.
Michal [unhandled content-type:application/pgp-signature] | ![\](/images/icornerr.gif) |