On Mon, 15 Jan 2024, Ale Crismani wrote: > > Il giorno 14 gen 2024, alle ore 21:38, Ale Crismani <ale.crismani@xxxxxxxxxxxxxx> ha scritto: > > > >> Il giorno 14 gen 2024, alle ore 06:30, David Wang <00107082@xxxxxxx> ha scritto: > >> > >> > >> At 2024-01-14 02:24:07, "Jozsef Kadlecsik" <kadlec@xxxxxxxxxxxxxxxxx> wrote: > >>> On Thu, 11 Jan 2024, David Wang wrote: > >>> > >>>> I tested the patch with code stressing swap->destroy->create->add 10000 > >>>> times, the performance regression still happens, and now it is > >>>> ip_set_destroy. (I pasted the test code at the end of this mail) > >> > >>>> > >>>> They all call wait_for_completion, which may sleep on something on > >>>> purpose, I guess... > >>> > >>> That's OK because ip_set_destroy() calls rcu_barrier() which is needed to > >>> handle flush in list type of sets. > >>> > >>> However, rcu_barrier() with call_rcu() together makes multiple destroys > >>> one after another slow. But rcu_barrier() is needed for list type of sets > >>> only and that can be handled separately. So could you test the patch > >>> below? According to my tests it is even a little bit faster than the > >>> original code before synchronize_rcu() was added to swap. > >> > >> Confirmed~! This patch does fix the performance regression in my case. > >> > >> Hope it can fix ale.crismani@xxxxxxxxxxxxxx's original issue. > > > > Thanks for all the help on this, I'll try the patch tomorrow hopefully > > and will report back! > > I applied the patch on 6.1.y on top of 875ee3a and I can confirm it > fixes the performance issues in our case too. Thanks for the testing, to both of you. I'm going to release the patch for kernel inclusion. Best regards, Jozsef -- E-mail : kadlec@xxxxxxxxxxxxxxxxx, kadlecsik.jozsef@xxxxxxxxx PGP key : https://wigner.hu/~kadlec/pgp_public_key.txt Address : Wigner Research Centre for Physics H-1525 Budapest 114, POB. 49, Hungary
