cygwin performance problem

Corinna Vinschen vinschen at
Fri Apr 21 20:15:06 EST 2006

On Apr 21 07:47, Damien Miller wrote:
> On Thu, 20 Apr 2006, Corinna Vinschen wrote:
> > However, while looking deeper into what's going on, it seems the bad
> > results are somehow based on a strange interaction between ssh and scp,
> > which triggers a performance problem in Cygwin.  Writing to the pipe to
> > scp and reading from the pipe in scp seem to take a lot of time. 
> Cygwin is set to use pipes instead of socketpairs for communication
> between scp/sftp and ssh, and between sshd and its subprocesses. 
> Perhaps you could try commenting out the
> 	AC_DEFINE(USE_PIPES, 1, [Use PIPES instead of a socketpair()])
> line under the cygwin host case value in, or just deleting
> the "#define USE_PIPES" from the generated config.h. If performance 
> improves it might indicate a problem with Cygwin's pipe implementation.

I did that already, but afaics scp always uses pipes for copying files
over ssh, or did I miss something?


Corinna Vinschen
Cygwin Project Co-Leader
Red Hat

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