Messages in this thread | | | Date | Fri, 13 Jul 2007 00:44:49 +1000 | From | David Chinner <> | Subject | Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) |
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On Thu, Jul 12, 2007 at 01:14:36PM +0200, Andrea Arcangeli wrote: > On Thu, Jul 12, 2007 at 10:12:56AM +1000, David Chinner wrote: > > I need really large filesystems that contain both small and large files to > > work more efficiently on small boxes where we can't throw endless amounts of > > RAM and CPUs at the problem. Hence things like 64k page size are just not an > > option because of the wastage that it entails. > > I didn't know you were allocating 4k pages for the small files and 64k > for the large ones in the same fs. That sounds quite a bit > overkill.
We already have rudimentary multi-block size support via the per-inode extent size hint, but we still cache based on the filesystem block size ('coz we can't increase it).
All I want is to be able to change the index granularity in the page cache with minimal impact and everything in XFS falls almost straight out in a pretty optimal manner.
> I still think you should run those systems with PAGE_SIZE 64k even if > it'll waste you more memory on the small files.
That's crap. Just because a machine has lots of memory does not make it OK to waste lots of memory.
Cheers,
Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - 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/
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