Re: [patch v4 0/3] aio: implement request batching [more performance numbers]

[Jens Axboe <jens.axboe@oracle.com>]

On Tue, Oct 06 2009, Jeff Moyer wrote:
> Here's a mail I got from Nathan Roberts.
> 
> Cheers,
> Jeff
> 
> ---
> 
> Similar test as before. I had to re-upload the files so comparing
> against last time isn't really apples-apples.
> 
> Disk is a cciss logical drive consisting of 12 SATA drives in a RAID6
> configuration with 128K stripes.
> 
> Test case 1 is to read 1 million random 40K files (no file is read
> more than once), 16 4K iocbs at a time, 100 threads.
> 
> Test case 2 is the same except 100,000 128K files are read.
> 
> Unit of measure is "files read per second".
> 
> 
> 40K
> -------------------------------------------------
> Kernel                              NOOP
> ------                              ----
> 2.6.30.5                            682
> 2.6.30.5 (w/o drop_caches)          718
> 2.6.30.5+patch_v4                   900
> 2.6.30.5+patch_v4 (w/o drop caches) 965
> 
> 
> 128K
> -------------------------------------------------
> Kernel                              NOOP
> ------                              ----
> 2.6.30.5                            242
> 2.6.30.5 (w/o drop_caches)          350
> 2.6.30.5+patch_v4                   292
> 2.6.30.5+patch_v4 (w/o drop caches) 420

Nice numbers! The patch looks good to me from a quick look, if you want
I can throw it into the testing mix tomorrow and see what kind of
improvements I see here. With performance increase of that magnitude, we
should get it in sooner rather than later.

-- 
Jens Axboe