Hi Linus, > On Apr 24, 2022, at 10:43 AM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > [ I see that you posted a new version of the series, but I wasn't cc'd > on that one, so I'm replying to the old thread instead ] Thanks for fixing up these, and sorry for the messing up CC list. > > On Sat, Apr 16, 2022 at 12:55 PM Song Liu <songliubraving@xxxxxx> wrote: >> >> Patch 2/4 enables huge pages for large hash. > > I decided that for 5.18, we want to at least fix the performance > regression on powerpc, so I've applied the 2/4 patch to enable huge > pages for the large hashes. > > I also enabled them for kvmalloc(), since that seemed like the one > ObviouslySafe(tm) case of vmalloc use (famous last words, maybe I'll > be informed of somebody who still did odd protection games on the > result, but that really sounds invalid with the whole SLUB component). > > I'm not touching the bpf parts. I think that's a 5.19 issue by now, > and since it's new, there's no equivalent performance regression > issue. With 5.18-rc4, bpf programs on x86_64 are using 4kB bpf_prog_pack. So multiple small BPF programs will share a 4kB page. We still need to initialize each 4kB bpf_prog_pack with illegal instructions, with something similar to [1]. I will revise it based on Peter’s suggestion [2]. Thanks, Song [1] https://lore.kernel.org/all/20220422051813.1989257-2-song@xxxxxxxxxx/ [2] https://lore.kernel.org/linux-mm/20220422073118.GR2731@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
