On 8 September 2017 at 06:10, Brandon Schwartz <schwartz.xn@xxxxxxxxx> wrote: > On Thu, Sep 7, 2017 at 10:46 PM, Sitsofe Wheeler <sitsofe@xxxxxxxxx> wrote: >> >> On 8 September 2017 at 01:13, Brandon Schwartz <schwartz.xn@xxxxxxxxx> wrote: >>> >>> Running the following job file with --io_submit_mode=offload set will >>> occasionally give a 'No I/O performed by libaio' error [...] >>> >>> After a few minutes of running FIO will exit with the following >>> message: "No I/O performed by libaio, perhaps try --debug=io option >>> for details" >>> >>> With debug set, I see this near the end of the trace: >>> >>> io 7720 io complete: io_u 0x55e10ee4abc0: >>> off=1304219746304/len=65536/ddir=1io 7720 //dev/sdbio >>> 7720 >>> io 7720 fill_io_u: io_u 0x55e10ee4abc0: >>> off=233107357696/len=0/ddir=0io 7720 //dev/sdbio 7720 >> >> That's weird - fio tried to submit a zero length read. How big was your device? > > It's a 2TB drive OK this seems to reproduce the problem: ./fio --debug=io --name=zerolenread --size=1M --rw=randread --bs=128k,64k --ioengine=libaio --io_submit_mode=offload --filename=/tmp/zerolenread Perhaps offload is generating bad random offsets when the blocksizes between directions are different? -- 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
