On Tue, Feb 11 2003, Jens Axboe wrote:
> On Tue, Feb 11 2003, Jens Axboe wrote:
> > > Write based loads hurt. No breakages, but needs tuning.
> >
> > That's not even as bad as I had feared. I'll try to do some tuning with
> > contest locally.
>
> Here are my results, for 2.5.60 vanilla, 2.5.60 + cfq with default
> quantum of 16 (what you tested, too), and 2.5.60 + cfq without quantum
> setting. The latter should be the fairest, only moves one request from
> the pending queues.
Did runs with quantum values of 2,4,8 as well to see how it looks. Often
the dbench runs got screwed, perhaps the signalling changes from 2.5.60
is interfering?
dbench_load.c:72: SYSTEM ERROR: No such process : could not kill pid 4842
Anyways, here are the results:
no_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 31 177.4 0 0.0 1.00
2.5.60-cfq0 2 31 174.2 0 0.0 1.00
2.5.60-cfq16 2 31 177.4 0 0.0 1.00
2.5.60-cfq4 1 32 171.9 0 0.0 1.00
2.5.60-cfq8 2 31 174.2 0 0.0 1.00
cacherun:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 29 182.8 0 0.0 0.94
2.5.60-cfq0 2 28 192.9 0 0.0 0.90
2.5.60-cfq16 2 29 182.8 0 0.0 0.94
2.5.60-cfq4 1 29 186.2 0 0.0 0.91
2.5.60-cfq8 2 29 182.8 0 0.0 0.94
process_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 38 142.1 12 47.4 1.23
2.5.60-cfq0 2 41 129.3 16 61.0 1.32
2.5.60-cfq16 2 37 145.9 12 43.2 1.19
2.5.60-cfq4 1 36 150.0 11 44.4 1.12
2.5.60-cfq8 2 38 142.1 13 47.4 1.23
ctar_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 38 147.4 0 0.0 1.23
2.5.60-cfq0 2 36 155.6 0 0.0 1.16
2.5.60-cfq16 2 36 155.6 0 0.0 1.16
2.5.60-cfq4 1 36 155.6 0 0.0 1.12
2.5.60-cfq8 2 37 151.4 0 0.0 1.19
xtar_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 40 140.0 0 2.5 1.29
2.5.60-cfq0 2 37 148.6 0 2.7 1.19
2.5.60-cfq16 2 40 137.5 0 2.5 1.29
2.5.60-cfq4 1 37 148.6 0 2.7 1.16
2.5.60-cfq8 2 38 147.4 0 2.6 1.23
io_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 93 61.3 2 14.0 3.00
2.5.60-cfq0 4 103 54.4 2 12.6 3.32
2.5.60-cfq16 2 264 21.6 12 19.9 8.52
2.5.60-cfq4 1 97 57.7 3 15.5 3.03
2.5.60-cfq8 2 135 42.2 5 16.3 4.35
read_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 40 140.0 0 5.0 1.29
2.5.60-cfq0 2 39 143.6 0 5.1 1.26
2.5.60-cfq16 2 40 140.0 0 5.0 1.29
2.5.60-cfq4 1 39 143.6 0 5.1 1.22
2.5.60-cfq8 2 40 140.0 0 5.0 1.29
list_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 35 157.1 0 8.6 1.13
2.5.60-cfq0 2 35 160.0 0 8.6 1.13
2.5.60-cfq16 2 35 160.0 0 14.3 1.13
2.5.60-cfq4 1 36 155.6 0 8.3 1.12
2.5.60-cfq8 2 35 160.0 0 11.4 1.13
mem_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 50 116.0 75 10.0 1.61
2.5.60-cfq0 2 57 101.8 78 8.8 1.84
2.5.60-cfq16 2 60 96.7 80 8.2 1.94
2.5.60-cfq4 1 52 111.5 76 9.4 1.62
2.5.60-cfq8 2 50 114.0 75 9.8 1.61
dbench_load:
Kernel [runs] Time CPU% Loads LCPU% Ratio
2.5.60 2 36 155.6 12693 27.8 1.16
2.5.60-cfq0 1 35 157.1 12013 28.6 1.13
2.5.60-cfq16 2 37 151.4 14356 32.4 1.19
2.5.60-cfq8 1 35 157.1 12174 31.4 1.13
As I initialy expected, without having data to back it up, a non-zero
quantum value helps. 16 was too much though, 4 looks a good choice. At
least here.
-- Jens Axboe- 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/
This archive was generated by hypermail 2b29 : Sat Feb 15 2003 - 22:00:34 EST