On Sun, Dec 14, 2014 at 1:53 AM, Jens Axboe <axboe@xxxxxxxxx> wrote: > On 12/12/2014 05:23 PM, Stephen Nichols wrote: >> Hi all, >> >> When using fio configuration below.. >> >> [global] >> ioengine=libaio >> direct=1 >> runtime=600 >> bs=32k >> iodepth=8 >> rw=randrw >> rwmixread=80 >> percentage_random=100,0 >> >> [drive1] >> filename=/dev/sda >> >> >> I am expecting to see 80% reads, 20% writes where all reads are random and all writes are sequential. I captured a bus trace of traffic to the disk and the bus trace reflected as much with one issue. The write commands are essentially random. Each write begins at a new random LBA. If 2 or more writes occur in a row, the LBA's are sequential based on the block size BUT I feel the heart of this feature would be to emulate a large file write during random access. With that in mind would it be possible for sequential reads or writes within mixed sequential/random workload to remember the last LBA accessed? In this scenario the writes would still only take up 20% of the workload but when a write did occur it should be the next sequential step from the last write. >> >> >> Snippet from the bus trace for reference >> >> Command LBA >> Read FPDMA Queued: 19F3F818 >> Read FPDMA Queued: 1CBE2740 >> Write FPDMA Queued: 24E35198 >> Write FPDMA Queued: 24E351A0 >> Read FPDMA Queued: 115A9E10 >> Write FPDMA Queued: A3C1968 >> Read FPDMA Queued: 20B89488 >> Write FPDMA Queued: 336EE0D0 >> Write FPDMA Queued: 336EE0D8 >> >> >> >> Let me know what you think, this feature may be working as intended but it seemed off to me. > > Would be easy enough to fix, we just need to track last offset per data > direction. Does the attached work for you? Totally untested, will test > on Monday. Looks like fixed. Regards, Andrey io 8568 load ioengine libaio drive1: (g=0): rw=randrw, bs=32K-32K/32K-32K/32K-32K, ioengine=libaio, iodepth=8 fio-2.1.14-45-g7003 Starting 1 process io 8570 invalidate cache /tmp/drive1: 0/1048576 io 8570 get_next_block: last read pos 0 io 8570 fill_io_u: io_u 0x176be40: off=32768/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176be40: off=32768/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176be40)=0 io 8570 queue: io_u 0x176be40: off=32768/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 1 io 8570 get_next_block: last read pos 65536 io 8570 fill_io_u: io_u 0x176bb40: off=753664/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176bb40: off=753664/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176bb40)=0 io 8570 queue: io_u 0x176bb40: off=753664/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 2 io 8570 get_next_block: last read pos 786432 io 8570 fill_io_u: io_u 0x176b400: off=851968/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176b400: off=851968/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176b400)=0 io 8570 queue: io_u 0x176b400: off=851968/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 3 === io 8570 get_next_block: last write pos 0 io 8570 fill_io_u: io_u 0x176b100: off=0/len=32768/ddir=1//tmp/drive1 io 8570 prep: io_u 0x176b100: off=0/len=32768/ddir=1//tmp/drive1 io 8570 ->prep(0x176b100)=0 io 8570 queue: io_u 0x176b100: off=0/len=32768/ddir=1//tmp/drive1 io 8570 calling ->commit(), depth 4 io 8570 get_next_block: last read pos 884736 io 8570 fill_io_u: io_u 0x176ae00: off=491520/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176ae00: off=491520/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176ae00)=0 io 8570 queue: io_u 0x176ae00: off=491520/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 5 io 8570 get_next_block: last read pos 524288 io 8570 fill_io_u: io_u 0x176ab00: off=393216/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176ab00: off=393216/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176ab00)=0 io 8570 queue: io_u 0x176ab00: off=393216/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 6 io 8570 get_next_block: last read pos 425984 io 8570 fill_io_u: io_u 0x176a840: off=0/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176a840: off=0/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176a840)=0 io 8570 queue: io_u 0x176a840: off=0/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 7 io 8570 get_next_block: last read pos 32768 io 8570 fill_io_u: io_u 0x176a540: off=65536/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176a540: off=65536/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176a540)=0 io 8570 queue: io_u 0x176a540: off=65536/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176b100: off=0/len=32768/ddir=1//tmp/drive1 io 8570 get_next_block: last read pos 98304 io 8570 fill_io_u: io_u 0x176b100: off=360448/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176b100: off=360448/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176b100)=0 io 8570 queue: io_u 0x176b100: off=360448/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176a840: off=0/len=32768/ddir=0//tmp/drive1 === io 8570 get_next_block: last write pos 32768 io 8570 fill_io_u: io_u 0x176a840: off=32768/len=32768/ddir=1//tmp/drive1 io 8570 prep: io_u 0x176a840: off=32768/len=32768/ddir=1//tmp/drive1 io 8570 ->prep(0x176a840)=0 io 8570 queue: io_u 0x176a840: off=32768/len=32768/ddir=1//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176a840: off=32768/len=32768/ddir=1//tmp/drive1 io 8570 get_next_block: last read pos 393216 io 8570 fill_io_u: io_u 0x176a840: off=950272/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176a840: off=950272/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176a840)=0 io 8570 queue: io_u 0x176a840: off=950272/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176be40: off=32768/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 983040 io 8570 fill_io_u: io_u 0x176be40: off=98304/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176be40: off=98304/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176be40)=0 io 8570 queue: io_u 0x176be40: off=98304/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176bb40: off=753664/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 131072 io 8570 fill_io_u: io_u 0x176bb40: off=884736/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176bb40: off=884736/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176bb40)=0 io 8570 queue: io_u 0x176bb40: off=884736/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176b400: off=851968/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 917504 io 8570 fill_io_u: io_u 0x176b400: off=655360/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176b400: off=655360/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176b400)=0 io 8570 queue: io_u 0x176b400: off=655360/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176ae00: off=491520/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 688128 io 8570 fill_io_u: io_u 0x176ae00: off=131072/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176ae00: off=131072/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176ae00)=0 io 8570 queue: io_u 0x176ae00: off=131072/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176ab00: off=393216/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 163840 io 8570 fill_io_u: io_u 0x176ab00: off=229376/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176ab00: off=229376/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176ab00)=0 io 8570 queue: io_u 0x176ab00: off=229376/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176a540: off=65536/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 262144 io 8570 fill_io_u: io_u 0x176a540: off=163840/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176a540: off=163840/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176a540)=0 io 8570 queue: io_u 0x176a540: off=163840/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176b100: off=360448/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 196608 io 8570 fill_io_u: io_u 0x176b100: off=557056/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176b100: off=557056/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176b100)=0 io 8570 queue: io_u 0x176b100: off=557056/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176a840: off=950272/len=32768/ddir=0//tmp/drive1 io 8570 get_next_block: last read pos 589824 io 8570 fill_io_u: io_u 0x176a840: off=458752/len=32768/ddir=0//tmp/drive1 io 8570 prep: io_u 0x176a840: off=458752/len=32768/ddir=0//tmp/drive1 io 8570 ->prep(0x176a840)=0 io 8570 queue: io_u 0x176a840: off=458752/len=32768/ddir=0//tmp/drive1 io 8570 calling ->commit(), depth 8 io 8570 io_u_queued_completed: min=1 io 8570 getevents: 1 io 8570 io complete: io_u 0x176be40: off=98304/len=32768/ddir=0//tmp/drive1 === io 8570 get_next_block: last write pos 65536 io 8570 fill_io_u: io_u 0x176be40: off=65536/len=32768/ddir=1//tmp/drive1 io 8570 prep: io_u 0x176be40: off=65536/len=32768/ddir=1//tmp/drive1 io 8570 ->prep(0x176be40)=0 io 8570 queue: io_u 0x176be40: off=65536/len=32768/ddir=1//tmp/drive1 > > -- > 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
