Re: [RFC PATCH] cfq-iosched: IOPS mode for group scheduling and newgroup_idle tunable

From: Heinz Diehl
Date: Sat Jul 24 2010 - 04:06:33 EST


On 23.07.2010, Vivek Goyal wrote:

> Anyway, for fs_mark problem, can you give following patch a try.
> https://patchwork.kernel.org/patch/113061/

Ported it to 2.6.35-rc6, and these are my results using the same fs_mark
call as before:

slice_idle = 0

FSUse% Count Size Files/sec App Overhead
28 1000 65536 241.6 39574
28 2000 65536 231.1 39939
28 3000 65536 230.4 39722
28 4000 65536 243.2 39646
28 5000 65536 227.0 39892
28 6000 65536 224.1 39555
28 7000 65536 228.2 39761
28 8000 65536 235.3 39766
28 9000 65536 237.3 40518
28 10000 65536 225.7 39861
28 11000 65536 227.2 39441


slice_idle = 8

FSUse% Count Size Files/sec App Overhead
28 1000 65536 502.2 30545
28 2000 65536 407.6 29406
28 3000 65536 381.8 30152
28 4000 65536 438.1 30038
28 5000 65536 447.5 30477
28 6000 65536 422.0 29610
28 7000 65536 383.1 30327
28 8000 65536 415.3 30102
28 9000 65536 397.6 31013
28 10000 65536 401.4 29201
28 11000 65536 408.8 29720
28 12000 65536 391.2 29157

Huh...there's quite a difference! It's definitely the slice_idle settings
which affect the results here. Besides, this patch gives noticeably bad
desktop interactivity on my system.

Don't know if this is related, but I'm not quite shure if XFS (which I use
exclusively) uses the jbd/jbd2 journaling layer at all.

Thanks,
Heinz.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/