lkml.org 
[lkml]   [2010]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: vmalloc performance
From
Date
Hi,

On Fri, 2010-04-16 at 01:51 +0900, Minchan Kim wrote:
[snip]
> Thanks for the explanation. It seems to be real issue.
>
> I tested to see effect with flush during rb tree search.
>
> Before I applied your patch, the time is 50300661 us.
> After your patch, 11569357 us.
> After my debug patch, 6104875 us.
>
> I tested it as changing threshold value.
>
> threshold time
> 1000 13892809
> 500 9062110
> 200 6714172
> 100 6104875
> 50 6758316
>
My results show:

threshold time
100000 139309948
1000 13555878
500 10069801
200 7813667
100 18523172
50 18546256

> And perf shows smp_call_function is very low percentage.
>
> In my cases, 100 is best.
>
Looks like 200 for me.

I think you meant to use the non _minmax version of proc_dointvec too?
Although it doesn't make any difference for this basic test.

The original reporter also has 8 cpu cores I've discovered. In his case
divided by 4 cpus where as mine are divided by 2 cpus, but I think that
makes no real difference in this case.

I'll try and get some further test results ready shortly. Many thanks
for all your efforts in tracking this down,

Steve.




\
 
 \ /
  Last update: 2010-04-16 16:13    [W:2.384 / U:1.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site