On Mon 03-04-23 11:23:25, Jens Axboe wrote: > On 4/3/23 11:15?AM, Amir Goldstein wrote: > >> On 4/3/23 11:00?AM, Amir Goldstein wrote: > >> io_uring does do it for non-polled IO, I don't think there's much point > >> in adding it to IOPOLL however. Not really seeing any use cases where > >> that would make sense. > >> > > > > Users subscribe to fsnotify because they want to be notified of changes/ > > access to a file. > > Why do you think that polled IO should be exempt? > > Because it's a drastically different use case. If you're doing high > performance polled IO, then you'd never rely on something as slow as > fsnotify to tell you of any changes that happened to a device or file. > That would be counter productive. Well, I guess Amir wanted to say that the application using fsnotify is not necessarily the one doing high performance polled IO. You could have e.g. data mirroring application A tracking files that need mirroring to another host using fsnotify and if some application B uses high performance polled IO to modify a file, application A could miss the modified file. That being said if I look at exact details, currently I don't see a very realistic usecase that would have problems (people don't depend on FS_MODIFY or FS_ACCESS events too much, usually they just use FS_OPEN / FS_CLOSE), which is likely why nobody reported these issues yet :). Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
