On Fri, Oct 30 2009, Chris Worley wrote: > On Fri, Oct 30, 2009 at 9:20 AM, Chris Worley <worleys@xxxxxxxxx> wrote: > > I'm running fio benchmarks for 120 hours: > > > > fio --rw=randrw --bs=4k --rwmixread=60 --numjobs=64 --iodepth=64 > > --sync=0 --direct=1 --randrepeat=0 --ioengine=libaio > > --filename=/dev/sde --filename=/dev/sdf --name=test --loops=10000 > > --size=322122547200 --runtime=432000 --group_reporting > > > > The fio threads are generally reporting 100K IOPS and each of the 64 > > fio threads uses less than 10% CPU. > > > > But, every 13 hours (nearly to the minute), for ~200 seconds, the FIO > > threads start consuming large amounts of CPU, and the IOPS drop to > > ~40K: > > Josh is brilliant: > > (322122547200[bytes per test]*64[threads])/(4096[block > size]*100000[IOPS]*3600[seconds per hour])=13 hours > > ...it's restarting the next loop and recalculating the random maps > every 13 hours Awesome! It should just give it or re-clean the random map, that is likely where the bug is. Looking forward to a tested patch :-) -- Jens Axboe -- 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
