[dm-devel] [PATCHES] improve sysfs performance, make it O(log n)

[Joe Thornber]

On Wed, Jul 20, 2011 at 06:56:50PM -0400, Mikulas Patocka wrote:
> Performance testing --- 10000 dm devices created with dmsetup:
> 
> The numbers are time in seconds to perform these operations:
> 1. create 10000 devices
> 2. ls -la /sys/block
> 3. ls -al /sys/block after a cache flush (echo 3 >/proc/sys/vm/drop_caches)
> 4. dmsetup remove_all
> 
> no patches	109	9.8	12	1624
> patch 1		109	9.1	12	15
> patches 1,2	120	0.19	3.0	16
> patches 1,2,3	68	0.17	0.47	12
> patches 1,2,3,4	68	0.15	0.48	11
> all patches	37	0.16	0.46	3.3

Fantastic improvement Mikulas!