On 13 August 2014 21:15, Jens Axboe <axboe@xxxxxxxxx> wrote: > On 08/11/2014 10:56 PM, Sitsofe Wheeler wrote: >> >> Yup that fixes it. I've got one more mismatch query although with a >> different job file: >> >> fio --thread --direct=1 --ioengine=libaio --iodepth=128 --bs=64k >> --rw=randwrite --verify=xxhash --verify_backlog=50 --filename >> /dev/sdaw --name=go --time_based --runtime=2m --size=1M >> >> I've got a case where this generates verification error before the job >> completes. However on most of the other disks I have tried (virtual >> disks, RAM disks etc) this job runs without issues. Once again >> replacing --time_based --runtime with --loops makes the issue go >> aways. Further, switching the ioscheduler for this disk from cfq to >> noop also makes the problem go away (I've disabled merging by echoing >> 1 into nomerges)... >> >> Could it be this job submits different I/O to the same position in the >> same batch? If so isn't the result undefined? Why would using noop >> solve the issue? > > It's most likely a bug that is timing dependent, which is why certain > changes to the IO path below fio will make a difference. I'll take a > look at this. I've got some logs from fio-2.1.11-11-gb7f5 and a blktrace from 3.14.2-200.fc20.x86_64 on http://sucs.org/~sits/test/fio/fio-trace.tar.bz2 - does this help? -- Sitsofe | http://sucs.org/~sits/ -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
