Re: Major regression on hackbench with SLUB (more numbers)

Ingo Molnar
2007-12-11T14:34:18Z

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Hackbench seems to show this regression the most. In my tests I didn't
> see much change with kernel builds and such, but the focus was on
> scheduling not memory management. I'll run my kernel tests next for
> both SLAB and SLUB and see if there's any difference there.

i just ran various benchmarks on an 8-way (8x 700 MHz Xeon, 4GB RAM):

AVG v2.6.24.slab v2.6.24.slub [ smaller is better ]
-----------------------------------------
mmap: 1052.66 1049.33 ( 0%)
ctx-2: 4.32 4.30 ( 0%)
select: 41.95 43.69 ( 4%)
proc-exec: 394.45 391.92 ( 0%)
hackbench-10: 1.12 2.99 (166%)
hackbench-20: 2.04 6.67 (226%)
hackbench-50: 5.03 17.50 (247%)

and hackbench overhead stands out, by a huge margin. Other stuff is
within measurement noise. Neither SLUB nor SLAB debugging was turned on,
all other debugging options were off too.

Ingo