X-Recipient: archive-cygwin AT delorie DOT com X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Date: Mon, 8 Mar 2010 05:19:51 +0000 From: Jamie Lokier To: Wayne Davison Cc: Eliot Moss , rsync AT lists DOT samba DOT org, cygwin Subject: Re: cygwin + rsync issue under Windows 7 x64 Message-ID: <20100308051951.GB24024@shareable.org> References: <4B8440BF DOT 8050403 AT cs DOT umass DOT edu> <733654e31003060921mca36c77j154e5af4440c568a AT mail DOT gmail DOT com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <733654e31003060921mca36c77j154e5af4440c568a@mail.gmail.com> User-Agent: Mutt/1.5.13 (2006-08-11) Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Wayne Davison wrote: > I'd imagine that both ssh and rsync start using a lot of CPU because > the socketpair must be indicating that it is ready for a write (or > read) but the actual write() (or read()) fails to return any bytes (as > long as errno is something like EAGAIN, EINTR, or EWOULDBLOCK, rsync > will try again). Ā If you want to test that theory, you could add some > prints to rsync's io.c file near the 3 uses of EWOULDBLOCK and have it > output what errno it gets. Ā If you get that fixed, the programs that > interface with a socketpair should go back to normal. It would not be the first time Cygwin did something like that. 11.5 years ago, Cygwin32 b19.1, I found it returning EAGAIN continuously when reading from pipes to a child process and from the master side of a pty to a child process, while select() indicated "ready for exception" (at least from the pty master; I don't remember if it was that or "ready for read" from a pipe). How interesting that sockpair() now looks like having a similar problem. Perhaps the sockpair problem might be related to the getting stuck people occasionally report with rsync + ssh + Cygwin ? I.e. maybe disabling socketpair() will fix the stuck problem too? Maybe the next time someone encounters it, they'll google this thread, try it and let us know how it went, thanks :) -- Jamie -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple