On Mon, Jan 10, 2022 at 9:25 AM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > About the issue of serializing concurrent writes for > cgroup_pressure_write() similar to how psi_write() does. Doesn't > of->mutex inside kernfs_fop_write_iter() serialize the writes to the > same file? Ahh, yes, it looks like that does solve the serialization issue. Sorry, I missed that because I'm not actually all that familiar with the kernfs 'of' code. So the only issue is the trigger lifetime one, and if a single trigger is sufficient and returning -EBUSY for trying to replace an existing one is good, then I think that's the proper fix. I'm very busy with the merge window (and some upcoming travel and family events), so I'm hoping somebody will write and test such a patch. Please? Linus