On Fri, May 21, 2021 at 11:44 AM Andrei Vagin <avagin@xxxxxxxxxx> wrote: > > > > On Thu, May 20, 2021 at 11:36 AM Peter Oskolkov <posk@xxxxxxxxxx> wrote: >> >> As indicated earlier in the FUTEX_SWAP patchset: >> >> https://lore.kernel.org/lkml/20200722234538.166697-1-posk@xxxxxxx/ > > > Hi Peter, > > Do you have benchmark results? How fast is it compared with futex_swap and the google switchto? Hi Andrei, I did not run benchmarks on the same machine/kernel, but umcg_swap between "core" tasks (your use case for gVisor) should be somewhat faster than futex_swap, as there is no reading from the userspace and no futex hash lookup/dequeue ops; umcg_swap should be slower than switchto_switch because umcg_swap does go through ttwu+schedule, which switchto_switch bypasses. I expect that if UMCG is merged in a form similar to what I posted, we will explore how to make UMCG context switches faster in later patches. Thanks, Peter > > Thanks, > Andrei
