On Sun, Aug 14, 2022, at 4:28 PM, Chris Murphy wrote: > On Fri, Aug 12, 2022, at 2:02 PM, Jens Axboe wrote: >> Might be worth trying to revert those from 5.12 to see if they are >> causing the issue? Jan, Paolo - does this ring any bells? > > git log --oneline --no-merges v5.11..c03c21ba6f4e > bisect.txt > > I tried checking out a33df75c6328, which is right before the first bfq > commit, but that kernel won't boot the hardware. > > Next I checked out v5.12, then reverted these commits in order (that > they were found in the bisect.txt file): > > 7684fbde4516 bfq: Use only idle IO periods for think time calculations > 28c6def00919 bfq: Use 'ttime' local variable > 41e76c85660c bfq: Avoid false bfq queue merging >>>>a5bf0a92e1b8 bfq: bfq_check_waker() should be static > 71217df39dc6 block, bfq: make waker-queue detection more robust > 5a5436b98d5c block, bfq: save also injection state on queue merging > e673914d52f9 block, bfq: save also weight-raised service on queue merging > d1f600fa4732 block, bfq: fix switch back from soft-rt weitgh-raising > 7f1995c27b19 block, bfq: re-evaluate convenience of I/O plugging on rq arrivals > eb2fd80f9d2c block, bfq: replace mechanism for evaluating I/O intensity >>>>1a23e06cdab2 bfq: don't duplicate code for different paths > 2391d13ed484 block, bfq: do not expire a queue when it is the only busy > one > 3c337690d2eb block, bfq: avoid spurious switches to soft_rt of > interactive queues > 91b896f65d32 block, bfq: do not raise non-default weights > ab1fb47e33dc block, bfq: increase time window for waker detection > d4fc3640ff36 block, bfq: set next_rq to waker_bfqq->next_rq in waker > injection > b5f74ecacc31 block, bfq: use half slice_idle as a threshold to check > short ttime > > The two commits prefixed by >>> above were not previously mentioned by > Jens, but I reverted them anyway because they showed up in the git log > command. > > OK so, within 10 minutes the problem does happen still. This is > block/bfq-iosched.c resulting from the above reverts, in case anyone > wants to double check what I did: > https://drive.google.com/file/d/1ykU7MpmylJuXVobODWiiaLJk-XOiAjSt/view?usp=sharing Any suggestions for further testing? I could try go down farther in the bisect.txt list. The problem is if the hardware falls over on an unbootable kernel, I have to bug someone with LOM access. That's a limited resource. -- Chris Murphy
