Messages in this thread | | | From | Con Kolivas <> | Subject | Re: [BENCHMARK] 2.5.47-mm3 with contest | Date | Sat, 16 Nov 2002 22:13:28 +1100 |
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>Andrew Morton wrote: >>Con Kolivas wrote: >>>Note the significant discrepancy between mm1 and mm3. This reminds me of >>> what happened last time I enabled shared 3rd level pagetables - Andrew do >>> you want me to do a set of numbers with this disabled? >> >>That certainly couldn't hurt. But your tests are, in general, tesging >>the IO scheduler. And the IO scheduler has changed radically in each >>of the recent -mm's. >> >>So testing with rbtree-iosched reverted would really be the only way >>to draw comparisons on how the rest of the code is behaving. >>- >>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >>the body of a message to majordomo@vger.kernel.org >>More majordomo info at http://vger.kernel.org/majordomo-info.html >>Please read the FAQ at http://www.tux.org/lkml/ > >Andrew there is, in fact a problem with the io scheduler in mm3 as far >as I can see. Jens is away 'till Monday so he hasn't confirmed this yet. >Basically if the device can't get through the entire queue within the >read|write_expire timeout, they will start being submitted in fifo order >slowing down the device more (probably) and contributing to the problem. >It may be causing the bad numbers in contest. Here is a patch which >relieves the problem for loads I am testing (bench.c, tiobench). > >Con, it would be nice if you could try this, if you value your disk, >maybe you could wait for Jens to get back!
I gave it a quick run (with expire batch set to 16 to emulate fifo batch=16) and found only these different:
2.5.47-mm3ns is no shared 3rd level pagetables 2.5.47-mm3u is the same as 2.5.47-mm3ns but with your update
io_load: Kernel [runs] Time CPU% Loads LCPU% Ratio 2.5.47-mm3ns [1] 121.8 60 5 7 1.71 2.5.47-mm3u [1] 161.1 47 9 9 2.26
read_load: Kernel [runs] Time CPU% Loads LCPU% Ratio 2.5.47-mm3ns [2] 257.9 29 11 2 3.61 2.5.47-mm3u [1] 283.4 27 12 2 3.97
mem_load: Kernel [runs] Time CPU% Loads LCPU% Ratio 2.5.47-mm3ns [1] 237.5 32 41 1 3.33 2.5.47-mm3u [1] 218.8 34 39 1 3.06
To me it does not appear to be the cause of the prolongation of kernel compilation time under io load in 2.5.47-mm3
Con -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.0 (GNU/Linux)
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