RE: [PATCH] backing dev unplugging

Kenneth Chen
2004-03-15T05:54:23Z

>>>>>> Andrew Morton on Wed March 10, 2004 11:56 AM
>Jens Axboe <axboe@suse.de> wrote:
>> Here's a first cut at killing global plugging of block devices to reduce
>> the nasty contention blk_plug_lock caused. This introduceds per-queue
>> plugging, controlled by the backing_dev_info.
>
>This is such an improvement over what we have now it isn't funny.
>
>Ken, the next -mm is starting to look like linux-3.1.0 so I think it
>would be best if you could benchmark Jens's patch against 2.6.4-rc2-mm1.

Our latest measurement on the 32P, 1000 disks setup indicates this patch
is working as expected performance wise. We saw 200% improvement on the
throughput compare to global blk_plug_list. (compare to the per-cpu
blk_plug_list, performance is the same).

- Ken