X-Spam-Check-By: sourceware.org Date: Tue, 14 Mar 2006 17:43:04 -0500 From: Christopher Faylor To: cygwin@cygwin.com Subject: Re: select() too slow Message-ID: <20060314224304.GC7159@trixie.casa.cgf.cx> Reply-To: cygwin@cygwin.com References: <1753CE61-D772-46F7-8393-84E419E49307@ptnix.com> <4412EF74.1070500@byu.net> <890F74C6-8E51-405F-86CC-551170A2EA70@honeynet-pt.org> <20060311181653.GA10054@trixie.casa.cgf.cx> <20060314191855.GA17565@trixie.casa.cgf.cx> <1B24AE67-B28C-4D8E-A655-5D42E92B7F0C@honeynet-pt.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1B24AE67-B28C-4D8E-A655-5D42E92B7F0C@honeynet-pt.org> User-Agent: Mutt/1.5.11 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com On Tue, Mar 14, 2006 at 09:42:25PM +0000, Pedro Inacio wrote: >I'm goin to explain everything step by step in order to be now doubts. > >One computer with dual boot, Linux in one partition and Windows with >Cygwin installed on another partition. > >Boot on Linux compile echo_server.c, run it and it will listen on tcp >port 12345 >Imagine that the IP address of the system is 192.168.1.1 > >Go to some other Linux system on the network, create or choose some >"big_file" you have there and run: > >time cat big_file | nc -w 1 192.168.1.1 12345 > /tmp/output > >Ok, before w is a dash, it's a matter of charset encoding. >What this command will do is it will cat the big_file and send data >via nc (netcat) to the system where the echo_server is running, then >the echo_server receives the data and sends it back. When done you >will see how much time that process toke. The value 1 after w is to >disconnect nc after 1 second of timeout. > >This process, sending a 100 MB big_file takes 22 seconds on Linux. > >Now boot on Windows, and imagine that the IP address is 192.168.1.1, >run Cygwin compile echo_server.c, run it and do the same. >The same process takes now 4 minutes sending the same big_file. I don't have any 100MB files sitting around but when I tried this on a 14MB file, I find that cygwin is about 2X slower, not an order of magnitude slower. Taking away the pipe and using regular file redirection makes things a little faster on cygwin. So, I can't explain why you are seeing such extreme slowdowns. I am using the equivalent of a snapshot in my tests, however. Maybe that's the difference. cgf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/