On Sat, 31 Aug 2024, Chuck Lever wrote: > On Fri, 30 Aug 2024 17:03:15 +1000, NeilBrown wrote: > > I've been digging into wake_up_bit and wake_up_var recently. There are > > a lot of places where the required barriers aren't quite right. > > > > This patch fixes them up for nfsd. The bugs are mostly minor, though > > the rp_locked on might be a credible problem on weakly ordered hosts > > (e.g. power64). > > > > [...] > > Applied to nfsd-next for v6.12, thanks! > > [1/2] nfsd: use clear_and_wake_up_bit() > commit: 2b9a19d16beda1b2ca5edab47d74b73d4d958b12 > [2/2] nfsd: avoid races with wake_up_var() > commit: a2bf7d13821603fb90c3f6e695bd5fb4ee19de71 > > Both of these patches threw compilation errors. I corrected those > issues before applying. Please check my work. Thanks for that ... I really shouldn't post patches in the afternoon - I'm not thinking as clearly :-( > > checkpatch.pl complained about the lack of comment on the added > barriers. I felt the code was self-explanatory so made no change. > I'd really like a wake_up_var_after_atomic() but Linus wasn't keen on going in that direction. if/when my improvements land https://lore.kernel.org/all/20240826063659.15327-1-neilb@xxxxxxx/ we could change rp_locked to an "int" and use store_release_wake_up() which includes that required barrier. NeilBrown
