lkml.org 
[lkml]   [2008]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: What is the limit size of tmpfs /dev/shm ?
Hugh Dickins wrote:
> On Wed, 6 Feb 2008, H. Peter Anvin wrote:
>> That sounds like a problem in our overall swap handling, not specifically in
>> tmpfs. Now, I can't say anything concrete about heavy swap conditions, but in
>> light swap conditions I have measured a 20x performance improvement(!) over
>> ext3 on real workloads.
>
> Wow, I'm surprised. I suppose I do jump to thinking of heavy swapping
> when light swapping won't be so bad; but even so, 20x ext3 astonishes
> me - ext3 wouldn't be anyone's choice for fastest, but even so...
>
> I certainly guess too much and measure too little:
> is there a useful test you could point me to? TIA
>

The specific application was this:

- extract a kernel tarball
- "make distclean"
- cp -al the resulting tree
- apply a patch to each tree
- do a diff between the trees
- delete all files

... repeat something like 20,000 times.

-hpa


\
 
 \ /
  Last update: 2008-02-06 23:05    [from the cache]
©2003-2011 Jasper Spaans