On 3/15/24 10:23 AM, Pavel Begunkov wrote: > On 3/15/24 16:20, Jens Axboe wrote: >> On 3/15/24 9:30 AM, Pavel Begunkov wrote: >>> io_post_aux_cqe(), which is used for multishot requests, delays >>> completions by putting CQEs into a temporary array for the purpose >>> completion lock/flush batching. >>> >>> DEFER_TASKRUN doesn't need any locking, so for it we can put completions >>> directly into the CQ and defer post completion handling with a flag. >>> That leaves !DEFER_TASKRUN, which is not that interesting / hot for >>> multishot requests, so have conditional locking with deferred flush >>> for them. >> >> This breaks the read-mshot test case, looking into what is going on >> there. > > I forgot to mention, yes it does, the test makes odd assumptions about > overflows, IIRC it expects that the kernel allows one and only one aux > CQE to be overflown. Let me double check Yeah this is very possible, the overflow checking could be broken in there. I'll poke at it and report back. -- Jens Axboe
