On Tue, Mar 4, 2025 at 2:55 AM Vlastimil Babka <vbabka@xxxxxxx> wrote: > > On 2/25/25 21:26, Suren Baghdasaryan wrote: > > On Mon, Feb 24, 2025 at 1:12 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > >> > >> > > >> > > The values represent the total time it took to perform mmap syscalls, less is > >> > > better. > >> > > > >> > > (1) baseline control > >> > > Little core 7.58327 6.614939 (-12.77%) > >> > > Medium core 2.125315 1.428702 (-32.78%) > >> > > Big core 0.514673 0.422948 (-17.82%) > >> > > > >> > > (2) baseline control > >> > > Little core 7.58327 5.141478 (-32.20%) > >> > > Medium core 2.125315 0.427692 (-79.88%) > >> > > Big core 0.514673 0.046642 (-90.94%) > >> > > > >> > > (3) baseline control > >> > > Little core 7.58327 4.779624 (-36.97%) > >> > > Medium core 2.125315 0.450368 (-78.81%) > >> > > Big core 0.514673 0.037776 (-92.66%) > > > > (4) baseline control > > Little core 7.58327 4.642977 (-38.77%) > > Medium core 2.125315 0.373692 (-82.42%) > > Big core 0.514673 0.043613 (-91.53%) > > > > I think the difference between (3) and (4) is noise. > > Thanks, > > Suren. > > Hi, as we discussed yesterday, it would be useful to set the baseline to > include everything before sheaves as that's already on the way to 6.15, so > we can see more clearly what sheaves do relative to that. So at this point > it's the vma lock conversion including TYPESAFE_BY_RCU (that's not undone, > thus like in scenario (4)), and benchmark the following: > > - baseline - vma locking conversion with TYPESAFE_BY_RCU > - baseline+maple tree node reduction from mm-unstable (Liam might point out > which patches?) > - the above + this series + sheaves enabled for vm_area_struct cache > - the above + full maple node sheaves conversion [1] > - the above + the top-most patches from [1] that are optimizations with a > tradeoff (not clear win-win) so it would be good to know if they are useful > > [1] currently the 4 commits here: > https://web.git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git/log/?h=slub-percpu-sheaves-v2-maple > from "maple_tree: Sheaf conversion" to "maple_tree: Clean up sheaf" > but as Liam noted, they won't cherry pick without conflict once maple tree > node reduction is backported, but he's working on a rebase > > Thanks in advance! Sure, I'll run the tests and post results sometime later this week. Thanks! > > >> > > > >> > > Results in (3) vs (2) indicate that using sheaves for vm_area_struct > >> > > yields slightly better averages and I noticed that this was mostly due > >> > > to sheaves results missing occasional spikes that worsened > >> > > TYPESAFE_BY_RCU averages (the results seemed more stable with > >> > > sheaves). > >> > > >> > Thanks a lot, that looks promising! > >> > >> Indeed, that looks better than I expected :) > >> Cheers! > >> > >> > > >> > > [1] https://lore.kernel.org/all/20250213224655.1680278-1-surenb@xxxxxxxxxx/ > >> > > > >> > >
