On Tue, Oct 22, 2024 at 02:31:53PM +0800, Muchun Song wrote: > > > > On Oct 21, 2024, at 21:45, Jens Axboe <axboe@xxxxxxxxx> wrote: > > > > On 10/21/24 2:52 AM, Muchun Song wrote: > >> The memory barriers in list_del_init_careful() and list_empty_careful() > >> in pairs already handle the proper ordering between data.got_token > >> and data.wq.entry. So remove the redundant explicit barriers. And also > >> change a "break" statement to "return" to avoid redundant calling of > >> finish_wait(). > > > > Not sure why you didn't CC Omar on this one, as he literally just last > > week fixed an issue related to this. > > Hi Jens, > > Yes. I only CC the author of patch of adding the barriers, I thought > they should be more confident about this. Thanks for your reminder. > I saw Omar's great fix. And thanks for you help me CC Omar. I think > he'll be also suitable for commenting on this patch. > > Muchun, > Thanks. Well there goes my streak of not reading memory-barriers.txt for a few months... This looks fine to me. wake_up_process() also implies a full memory barrier, so I that smp_wmb() was extra redundant. Reviewed-by: Omar Sandoval <osandov@xxxxxx>
