On 8/15/20 9:48 AM, Pavel Begunkov wrote: > On 15/08/2020 18:12, Jens Axboe wrote: >> On 8/15/20 12:45 AM, Pavel Begunkov wrote: >>> On 13/08/2020 02:32, Jens Axboe wrote: >>>> On 8/12/20 12:28 PM, Pavel Begunkov wrote: >>>>> On 12/08/2020 21:22, Pavel Begunkov wrote: >>>>>> On 12/08/2020 21:20, Pavel Begunkov wrote: >>>>>>> On 12/08/2020 21:05, Jens Axboe wrote: >>>>>>>> On 8/12/20 11:58 AM, Josef wrote: >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> I have a weird issue on kernel 5.8.0/5.8.1, SIGINT even SIGKILL >>>>>>>>> doesn't work to kill this process(always state D or D+), literally I >>>>>>>>> have to terminate my VM because even the kernel can't kill the process >>>>>>>>> and no issue on 5.7.12-201, however if IOSQE_IO_LINK is not set, it >>>>>>>>> works >>>>>>>>> >>>>>>>>> I've attached a file to reproduce it >>>>>>>>> or here >>>>>>>>> https://gist.github.com/1Jo1/15cb3c63439d0c08e3589cfa98418b2c >>>>>>>> >>>>>>>> Thanks, I'll take a look at this. It's stuck in uninterruptible >>>>>>>> state, which is why you can't kill it. >>>>>>> >>>>>>> It looks like one of the hangs I've been talking about a few days ago, >>>>>>> an accept is inflight but can't be found by cancel_files() because it's >>>>>>> in a link. >>>>>> >>>>>> BTW, I described it a month ago, there were more details. >>>>> >>>>> https://lore.kernel.org/io-uring/34eb5e5a-8d37-0cae-be6c-c6ac4d85b5d4@xxxxxxxxx >>>> >>>> Yeah I think you're right. How about something like the below? That'll >>>> potentially cancel more than just the one we're looking for, but seems >>>> kind of silly to only cancel from the file table holding request and to >>>> the end. >>> >>> The bug is not poll/t-out related, IIRC my test reproduces it with >>> read(pipe)->open(). See the previously sent link. >> >> Right, but in this context for poll, I just mean any request that has a >> poll handler armed. Not necessarily only a pure poll. The patch should >> fix your case, too. > > Ok. I was thinking about sleeping in io_read(), etc. from io-wq context. > That should have the same effect. We already cancel any blocking work for the exiting task - but we do that _after_ trying to cancel files, so we should probably just swap those around in io_uring_flush(). That'll remove any need to find and cancel those explicitly in io_uring_cancel_files(). -- Jens Axboe
