Re: [PATCH 1/2] fs: Do not dispatch FITRIM through separatesuper_operation

[Christoph Hellwig]

On Fri, Nov 19, 2010 at 10:21:35AM -0500, Mark Lord wrote:
> >I really hate to rely on this third party hearsay (from all sides), and
> >have implement TRIM support in qemu now.  I'll soon install win7 and
> >will check out the TRIM patters myself.
> 
> Excellent!

I did a Windows 7 installation under qemu today, and the result is:

 - it TRIMs the whole device early during the installation
 - after that I see a constant stream of small trims during the
   installation.  It's using lots of non-contiguous ranges in a single
   TRIM command, with sizes down to 8 sectors (4k) for a single range.
 - after installation there's is some background-trimming going on
   even when doing no user interaction with the VM at all.
 - removing files leads to an instant stream of TRIMs, again vectored
   and of all sizes down to 4k.  Note that the TRIMs are a lot more
   instant than even with btrfs and -o discard, which delays most
   TRIMs until doing a sync.
--
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/