From mboxrd@z Thu Jan 1 00:00:00 1970 From: bgamari@gmail.com (Ben Gamari) Date: Wed, 21 Jan 2009 21:35:28 -0500 Subject: [ltt-dev] [RFC PATCH] block: Fix bio merge induced high I/O latency In-Reply-To: <720e76b80901201222m72ae2e98l972c81ef5886a12e@mail.gmail.com> References: <20090117004439.GA11492@Krystal> <20090117162657.GA31965@Krystal> <20090117190437.GZ30821@kernel.dk> <20090118211234.GA4913@Krystal> <20090119182654.GT30821@kernel.dk> <20090120021055.GA6990@Krystal> <20090120073709.GC30821@kernel.dk> <720e76b80901201222m72ae2e98l972c81ef5886a12e@mail.gmail.com> Message-ID: <1232591728.3782.6.camel@mercury.localdomain> I'm not sure if this will help, but I just completed another set of benchmarks using Jens' patch and a variety of device parameters. Again, I don't know if this will help anyone, but I figured it might help quantify the differences between device parameters. Let me know if there's any other benchmarking or testing that I can do. Thanks, - Ben mint maxt ========================================================== queue_depth=1, slice_async_rq=1, quantum=1, patched anticipatory 25 msec 4410 msec cfq 27 msec 1466 msec deadline 36 msec 10735 msec noop 48 msec 37439 msec ========================================================== queue_depth=1, slice_async_rq=1, quantum=4, patched anticipatory 38 msec 3579 msec cfq 35 msec 822 msec deadline 37 msec 10072 msec noop 32 msec 45535 msec ========================================================== queue_depth=1, slice_async_rq=2, quantum=1, patched anticipatory 33 msec 4480 msec cfq 28 msec 353 msec deadline 30 msec 6738 msec noop 36 msec 39691 msec ========================================================== queue_depth=1, slice_async_rq=2, quantum=4, patched anticipatory 40 msec 4498 msec cfq 35 msec 1395 msec deadline 41 msec 6877 msec noop 38 msec 46410 msec ========================================================== queue_depth=31, slice_async_rq=1, quantum=1, patched anticipatory 31 msec 6011 msec cfq 36 msec 4575 msec deadline 41 msec 18599 msec noop 38 msec 46347 msec ========================================================== queue_depth=31, slice_async_rq=2, quantum=1, patched anticipatory 30 msec 9985 msec cfq 33 msec 4200 msec deadline 38 msec 22285 msec noop 25 msec 40245 msec ========================================================== queue_depth=31, slice_async_rq=2, quantum=4, patched anticipatory 30 msec 12197 msec cfq 30 msec 3457 msec deadline 35 msec 18969 msec noop 34 msec 42803 msec On Tue, 2009-01-20 at 15:22 -0500, Ben Gamari wrote: > On Tue, Jan 20, 2009 at 2:37 AM, Jens Axboe wrote: > > On Mon, Jan 19 2009, Mathieu Desnoyers wrote: > >> * Jens Axboe (jens.axboe at oracle.com) wrote: > >> Yes, ideally I should re-run those directly on the disk partitions. > > > > At least for comparison. > > > > I just completed my own set of benchmarks using the fio job file > Mathieu provided. This was on a 2.5 inch 7200 RPM SATA partition > formatted as ext3. As you can see, I tested all of the available > schedulers with both queuing enabled and disabled. I'll test the Jens' > patch soon. Would a blktrace of the fio run help? Let me know if > there's any other benchmarking or profiling that could be done. > Thanks, > > - Ben > > > mint maxt > ========================================================== > queue_depth=31: > anticipatory 35 msec 11036 msec > cfq 37 msec 3350 msec > deadline 36 msec 18144 msec > noop 39 msec 41512 msec > > ========================================================== > queue_depth=1: > anticipatory 45 msec 9561 msec > cfq 28 msec 3974 msec > deadline 47 msec 16802 msec > noop 35 msec 38173 msec