On 11/16/20 9:48 AM, Pavel Begunkov wrote: > On 16/11/2020 16:33, Jens Axboe wrote: >> On 11/15/20 5:56 AM, Pavel Begunkov wrote: >>> As tasks now cancel only theirs requests, and inflight_wait is awaited >>> only in io_uring_cancel_files(), which should be called with ->in_idle >>> set, instead of keeping a separate inflight_wait use tctx->wait. >>> >>> That will add some spurious wakeups but actually is safer from point of >>> not hanging the task. >>> >>> e.g. >>> task1 | IRQ >>> | *start* io_complete_rw_common(link) >>> | link: req1 -> req2 -> req3(with files) >>> *cancel_files() | >>> io_wq_cancel(), etc. | >>> | put_req(link), adds to io-wq req2 >>> schedule() | >>> >>> So, task1 will never try to cancel req2 or req3. If req2 is >>> long-standing (e.g. read(empty_pipe)), this may hang. >> >> This looks like it's against 5.11, but also looks like we should add >> it for 5.10? > > Yeah, 5.10 completely slipped my mind, I'll resend I applied it to 5.10, and fixed up the 5.11 side of things. So all good, just wanted to confirm. -- Jens Axboe
