lkml.org 
[lkml]   [2001]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: speed difference between using hard-linked and modular drives?
On Fri, Nov 09, 2001 at 11:05:32AM +1100, Anton Blanchard wrote:
> We also need a way to satisfy very large allocations for the hashes (eg
> the pagecache hash). On a 32G machine we get awful performance on the
> pagecache hash because we can only get an order 9 allocation out of
> get_free_pages:
>
> http://samba.org/~anton/linux/pagecache/pagecache_before.png
>
> When switching to vmalloc the hash is large enough to be useful:
>
> http://samba.org/~anton/linux/pagecache/pagecache_after.png
>
> As pointed out by Davem and Ingo we should try and avoid vmalloc here
> due to tlb trashing.

Sounds like you need a better hash function instead.

-Andi

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:13    [W:0.187 / U:31.332 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site