Re: [BENCHMARK] 2.5.47{-mm1} with contest

Jens Axboe (axboe@suse.de)
Tue, 12 Nov 2002 10:20:45 +0100


On Tue, Nov 12 2002, Giuliano Pochini wrote:
>
> On 12-Nov-2002 Andrew Morton wrote:
> > Con Kolivas wrote:
> >>
> >> io_load:
> >> Kernel [runs] Time CPU% Loads LCPU% Ratio
> >> 2.4.18 [3] 474.1 15 36 10 6.64
> >> 2.4.19 [3] 492.6 14 38 10 6.90
> >> 2.5.46 [1] 600.5 13 48 12 8.41
> >> 2.5.46-mm1 [5] 134.3 58 6 8 1.88
> >> 2.5.47 [3] 165.9 46 9 9 2.32
> >> 2.5.47-mm1 [5] 126.3 61 5 8 1.77
> >>
> >
> > We've increased the kernel build speed by 3.6x while decreasing the
> > speed at which writes are retired by 5.3x.
>
> Did the elevator change between .46 and .47 ?

No, but the fifo_batch count (which controls how many requests are moved
sort list to dispatch queue) was halved. This gives lower latency, at
the possible cost of dimishing throughput.

-- 
Jens Axboe

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