Re: [PATCH 2/2] memcg : rewrite percpu countings with newinterfaces

From: Balbir Singh
Date: Mon Nov 09 2009 - 02:07:52 EST


* KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2009-11-06 17:55:45]:

> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>
> Now, alloc_percpu() alloc good dynamic allocations and
> Recent updates on percpu.h gives us following kind of ops
> - __this_cpu_add() etc...
> This is designed to be a help for reduce code size in hot-path
> and very useful to handle percpu area. Thanks for great works.
>
> This patch rewrite memcg's (not-good) percpu status with new
> percpu support macros. This decreases code size and instruction
> size. By this, this area is now NUMA-aware and may have performance
> benefit.
>
> I got good result in parallel pagefault test. (my host is 8cpu/2socket)
>
> before==
> Performance counter stats for './runpause.sh' (5 runs):
>
> 474070.055912 task-clock-msecs # 7.881 CPUs ( +- 0.013% )
> 35829310 page-faults # 0.076 M/sec ( +- 0.217% )
> 3803016722 cache-references # 8.022 M/sec ( +- 0.215% ) (scaled from 100.00%)
> 1104083123 cache-misses # 2.329 M/sec ( +- 0.961% ) (scaled from 100.00%)
>
> 60.154982314 seconds time elapsed ( +- 0.018% )
>
> after==
> Performance counter stats for './runpause.sh' (5 runs):
>
> 474919.429670 task-clock-msecs # 7.896 CPUs ( +- 0.013% )
> 36520440 page-faults # 0.077 M/sec ( +- 1.854% )
> 3109834751 cache-references # 6.548 M/sec ( +- 0.276% )
> 1053275160 cache-misses # 2.218 M/sec ( +- 0.036% )
>
> 60.146585280 seconds time elapsed ( +- 0.019% )
>
> This test is affected by cpu-utilization but I think more improvements
> will be found in bigger system.
>

Hi, Kamezawa-San,

Could you please post the IPC results as well?

--
Balbir
--
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/