Samba write throughput

[Jeremy Allison]

On Thu, Jan 27, 2011 at 09:24:57AM +0800, Jacky Lam wrote:
> On 1/27/2011 12:38 AM, Jeremy Allison wrote:
> >On Wed, Jan 26, 2011 at 05:51:13PM +0800, Jacky Lam wrote:
> >>Dear all,
> >>
> >>     I setup my Samba server on my machine and get 300Mbps for
> >>reading from server, but only 170Mbps for writing. I found that
> >>reading is use a more efficient way to do with sendfile(). But
> >>writing just use normal file IO and cause too many memory copy. Is
> >>there any way to trigger (from client) or force the server to use
> >>recvfile() instead?
> >http://wiki.samba.org/index.php/Linux_Performance
> >
> Thanks. It is new to me, but it doesn't answer why recvfile/splice
> implementation has not chance to be used when my XP are writing to
> it. Any other idea?

There is no such system call as recvfile (at least on Linux).
The code is implemented this way to alow OEM vendors to add
such a call to implement zero-copy on write calls. Isilon
did this in their storage stack.

I don't know what else you're asking.

Jeremy.