[linux-cifs-client] Re: [PATCH 6/6] cifs: don't retry on blocking sends

[Jeff Layton]

On Sun, 30 Nov 2008 19:02:22 -0600
"Steve French" <smfrench at gmail.com> wrote:

> Presumably there is slightly less overhead (since 99%+ of all tcp
> kernel send message calls don't timeout/retry) in not having to reset
> the send timeout over and over.   We need a longer send timeout for
> large writes (> 56K) than for typical requests (100 bytes or so for
> the header is all that is sent)... so presumably is more efficient to
> set a low timeout (somewhere from 1 to 5 seconds) and retry a few
> times for the large write case.
> 

I'm not sure I buy this...

Why not just set the sndtimeo for the maximum timeout needed? If 99%+
of all sends will not time out then there's little harm in letting the
send timeout be a longer for the small calls. If we're out of memory
to buffer the send, then we're out of memory. How does setting a short
timeout for small calls make this more efficient?

-- 
Jeff Layton <jlayton at redhat.com>