Re: What is the limit size of tmpfs /dev/shm ?

[H. Peter Anvin]

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
--
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/