IO scheduler based IO controller V10
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From: Mike Galbraith on 2 Oct 2009 14:40 On Fri, 2009-10-02 at 20:26 +0200, Jens Axboe wrote: > On Fri, Oct 02 2009, Mike Galbraith wrote: > > On Fri, 2009-10-02 at 20:04 +0200, Jens Axboe wrote: > > > > > I'm not too crazy about it either. How about just using 'desktop' since > > > this is obviously what we are really targetting? 'latency' isn't fully > > > descriptive either, since it may not necessarily provide the best single > > > IO latency (noop would). > > > > Grin. "Perfect is the enemy of good" :) > > Avg > > 16.24 175.82 154.38 228.97 147.16 144.5 noop > > 43.23 57.39 96.13 148.25 180.09 105.0 deadline > > Yep, that's where it falls down. Noop basically fails here because it > treats all IO as equal, which obviously isn't true for most people. But > even for pure read workloads (is the above the mixed read/write, or just > read?), latency would be excellent with noop but the desktop experience > would not. Yeah, it's the dd vs konsole -e exit. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Jens Axboe on 2 Oct 2009 14:50 On Fri, Oct 02 2009, Theodore Tso wrote: > On Fri, Oct 02, 2009 at 08:04:37PM +0200, Jens Axboe wrote: > > > i'd say 'latency' describes it even better. 'interactivity' as a term is > > > a bit overladen. > > > > I'm not too crazy about it either. How about just using 'desktop' since > > this is obviously what we are really targetting? 'latency' isn't fully > > descriptive either, since it may not necessarily provide the best single > > IO latency (noop would). > > As Linus has already pointed out, it's not necessarily "desktop" > versus "server". There will be certain high frequency transaction > database workloads (for example) that will very much care about > latency. I think "low_latency" may be the best term to use. Not necessarily, but typically it will be. As already noted, I don't think latency itself is a very descriptive term for this. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Mike Galbraith on 2 Oct 2009 15:00 On Fri, 2009-10-02 at 20:19 +0200, Jens Axboe wrote: > I'm not too worried about the "single IO producer" scenarios, and it > looks like (from a quick look) that most of your numbers are within some > expected noise levels. It's the more complex mixes that are likely to > cause a bit of a stink, but lets worry about that later. One quick thing > would be to read eg 2 or more files sequentially from disk and see how > that performs. Hm. git(s) should be good for a nice repeatable load. Suggestions? > If you could do a cleaned up version of your overload patch based on > this: > > http://git.kernel.dk/?p=linux-2.6-block.git;a=commit;h=1d2235152dc745c6d94bedb550fea84cffdbf768 > > then lets take it from there. I'll try to find a good repeatable git beater first. At this point, I only know it helps with one load. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Ingo Molnar on 2 Oct 2009 15:10 * Jens Axboe <jens.axboe(a)oracle.com> wrote: > On Fri, Oct 02 2009, Theodore Tso wrote: > > On Fri, Oct 02, 2009 at 08:04:37PM +0200, Jens Axboe wrote: > > > > i'd say 'latency' describes it even better. 'interactivity' as a term is > > > > a bit overladen. > > > > > > I'm not too crazy about it either. How about just using 'desktop' > > > since this is obviously what we are really targetting? 'latency' > > > isn't fully descriptive either, since it may not necessarily > > > provide the best single IO latency (noop would). > > > > As Linus has already pointed out, it's not necessarily "desktop" > > versus "server". There will be certain high frequency transaction > > database workloads (for example) that will very much care about > > latency. I think "low_latency" may be the best term to use. > > Not necessarily, but typically it will be. As already noted, I don't > think latency itself is a very descriptive term for this. Why not? Nobody will think of 'latency' as something that requires noop, but as something that in practice achieves low latencies, for stuff that people use. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Jens Axboe on 2 Oct 2009 15:10
On Fri, Oct 02 2009, Ingo Molnar wrote: > > * Jens Axboe <jens.axboe(a)oracle.com> wrote: > > > On Fri, Oct 02 2009, Theodore Tso wrote: > > > On Fri, Oct 02, 2009 at 08:04:37PM +0200, Jens Axboe wrote: > > > > > i'd say 'latency' describes it even better. 'interactivity' as a term is > > > > > a bit overladen. > > > > > > > > I'm not too crazy about it either. How about just using 'desktop' > > > > since this is obviously what we are really targetting? 'latency' > > > > isn't fully descriptive either, since it may not necessarily > > > > provide the best single IO latency (noop would). > > > > > > As Linus has already pointed out, it's not necessarily "desktop" > > > versus "server". There will be certain high frequency transaction > > > database workloads (for example) that will very much care about > > > latency. I think "low_latency" may be the best term to use. > > > > Not necessarily, but typically it will be. As already noted, I don't > > think latency itself is a very descriptive term for this. > > Why not? Nobody will think of 'latency' as something that requires noop, > but as something that in practice achieves low latencies, for stuff that > people use. Alright, I'll acknowledge that if that's the general consensus. I may be somewhat biased myself. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |