[linux-cifs-client] directio cifs more than doubled loopback file copy (write) perf

[Jeremy Allison]

On Thu, Dec 02, 2004 at 12:06:22PM -0600, Steve French wrote:
> Trying direct io in loopback network connection (cifs and samba on the
> same box).
> 
> The time for dd if=/dev/zero of=/mnt/testfile bs=256K count=200
> 
> went from more than 1.3 seconds on average without directio to 0.5
> seconds with mount -o directio
> 
> I did have a minor bug in the code to config it (I had marked an ifdef
> CIFS_EXPERIMENTAL instead of CONFIG_CIFS_EXPERIMENTAL) and will fix that
> and try to get the performance up a bit higher by eliminating a copy and
> sending more than 16K on writes.

In SVN I've fixed the LARGE_WRITEX issue so you should be able to
issue 128k writes.

Jeremy.