16 Aug
2022
16 Aug
'22
6:02 p.m.
On Tue, Aug 16, 2022 at 10:49 AM Jon Nettleton jon@solid-run.com wrote:
It is moot if Linus has already taken the patch, but with a stock kernel config I am still seeing a slight performance dip but only ~1-2% in the specific tests I was running.
It would be interesting to hear if you can pinpoint in the profiles where the time is spent.
It might be some random place that really doesn't care about ordering at all, and then we could easily rewrite _that_ particular case to do the unordered test explicitly, ie something like
- if (test_and_set_bit()) ... + if (test_bit() || test_and_set_bit()) ...
or even introduce an explicitly unordered "test_and_set_bit_relaxed()" thing.
Linus