On Mon, 10 Mar 2025 15:39:21 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 10 Mar 2025 10:23:09 -0700 SeongJae Park <sj@xxxxxxxxxx> wrote: > > > It is unclear if such use case > > is common and the inefficiency is significant. > > Well, we could conduct a survey, > > Can you add some logging to detect when userspace performs such an > madvise() call, then run that kernel on some "typical" machines which > are running "typical" workloads? That should give us a feeling for how > often userspace does this, I agree that could make this patch series more informative. > and hence will help us understand the usefulness > of this patchset. Nevertheless, what this patchset is really trying to optimize is not the madvise() use case, but process_madvise() use. I believe the usage is apparently common, given the vectorization based semantic of process_madvise(). Jemalloc is also adding[1] that kind of use case. And the benefit is clear, given the microbenchmark results that I shared. Also, this patchset shouldn't introduce new regression to madvise(). Hence, I think the survey can be interestign and helpful, but shouldn't be a blocker for this patch series. Coudl you please let me know if I'm missing something and if you still want the survey? [1] https://github.com/jemalloc/jemalloc/pull/2794 Thanks, SJ
