On Thu, Oct 24, 2024 at 4:33 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > On Thu, Oct 24, 2024 at 4:20 PM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > > On Thu, Oct 24, 2024 at 2:04 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > > > > > On Thu, Oct 24, 2024 at 9:28 AM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > > > > > > > On Thu, Oct 24, 2024 at 2:57 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > > > > > > > > On Wed, Oct 23, 2024 at 03:17:01PM -0700, Suren Baghdasaryan wrote: > > > > > > > > > > > > Or better yet, just use seqcount... > > > > > > > > > > > > Yeah, with these changes it does look a lot like seqcount now... > > > > > > I can take another stab at rewriting this using seqcount_t but one > > > > > > issue that Jann was concerned about is the counter being int vs long. > > > > > > seqcount_t uses unsigned, so I'm not sure how to address that if I > > > > > > were to use seqcount_t. Any suggestions how to address that before I > > > > > > move forward with a rewrite? > > > > > > > > > > So if that issue is real, it is not specific to this case. Specifically > > > > > preemptible seqcount will be similarly affected. So we should probably > > > > > address that in the seqcount implementation. > > > > > > > > Sounds good. Let me try rewriting this patch using seqcount_t and I'll > > > > work with Jann on a separate patch to change seqcount_t. > > > > Thanks for the feedback! > > > > > > I posted the patchset to convert mm_lock_seq into seqcount_t and to > > > add speculative functions at > > > https://lore.kernel.org/all/20241024205231.1944747-1-surenb@xxxxxxxxxx/. > > > > Thanks, Suren! Hopefully it can land soon! > > Would incorporating them into your patchset speed things up? If so, > feel free to include them into your series. I don't really think so. At this point the uprobe part is done (next revision has a comment style fix, that's all). So I'll just wait for your patches to be acked and applied, then I'll just do a trivial rebase. This will be easier for everyone at this point, IMO, to not couple them into a single patch set with two authors. Hopefully Peter will take those patches through tip/perf/core, though, so I don't have to wait for mm and tip trees to converge. > The only required change in your other patches is the renaming of > mmap_lock_speculation_start() to mmap_lock_speculation_begin(). Yep, no problem. > > > > > > > > > > > > > > >
