[Samba] sendfile

[Volker Lendecke]

On Thu, Jan 07, 2010 at 04:34:51PM -0500, Learner Study wrote:
> I just checked the manpage for 2.6.25 and it says the same. So, we are
> out of luck ;-(
> 
> Ok, so read (i.e. reading from disk and sending to socket) uses
> sendfile() but write involves two copies.
> 
> So, read performance should be way higher than write performance. What
> I notice is read is same as write in my case (have tried 3.0.21 and
> 3.0.25). Any ideas what could be causing that?

First, you have to enable sendfile with "use sendfile = yes"
explicitly. Second, read and write performance is affected
by MANY factors. Sendfile will have an impact if you have a
slow CPU, one with a slow memory subsystem or under very
high load. On a recent PC with just a few test clients,
those copies will definitely not be noticable.

Volker
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