Re: [PATCH (block.git) 0/2] IO CPU affinity update:

Jens Axboe
2008-03-17T19:27:27Z

On Mon, Mar 17 2008, Alan D. Brunelle wrote:
> Hi Jens -
>
> Two patches:
>
> 1. Adds in the IRQ saving to generic_smp_call_function_single_interrupt (as you had suggested).
> 2. Ensures a single IPI generated to get a remote function call handler going.
>
> So far it is working better than before on the 4-way IA64 w/ the mkfs/untar/make test suite - after 22 runs:
>
> Part RQ MIN AVG MAX Dev
> ----- -- ------ ------ ------ ------
> mkfs 0 18.786 19.253 19.655 0.241
> mkfs 1 18.639 19.182 19.786 0.293
>
> untar 0 17.140 17.486 18.250 0.322
> untar 1 16.951 17.494 18.274 0.350
>
> make 0 22.927 24.310 34.339 2.287
> make 1 22.863 23.788 24.189 0.333
>
> comb 0 59.478 61.049 70.320 2.142
> comb 1 59.875 60.463 61.305 0.458
>
> psys 0 3.96% 4.14% 4.39% 0.100
> psys 1 3.60% 3.85% 4.19% 0.176
>
> So we're seeing reduced time (~1.0%) and reduced %sys to do it (7.0%).
> The tighter deviations for make with rq=1 may be interesting... :-)
>
> I've compiled & booted the patches for x86_64 - rq=1 is working on
> that platform too.

This is starting to look pretty good! Thanks a lot for these results,
and the ->activated optimizations. I had a feeling the unstable results
were something like this, missing ipi's.

--
Jens Axboe