X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=-0.6 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org MIME-Version: 1.0 In-Reply-To: References: <786EBDA1AC46254B813E200779E7AD363AFE50@srv1163ex1.flightsafety.com> Date: Thu, 3 Sep 2009 08:34:45 -0400 Message-ID: Subject: Re: Simple bash script is slow to execute - appears to be time spent starting commands like ls From: Lee To: cygwin@cygwin.com Cc: "Thrall, Bryan" Content-Type: text/plain; charset=ISO-8859-1 X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: 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 9/2/09, David Tazartes wrote: > Bryan Thrall wrote: > > You're right about true being built-in, but we still don't know from > your examples whether the problem is from forking or from IO. Try > replacing 'true' in Jeremy's loop with '/bin/true'. Comparison between > the two should give us an idea of the forking cost, without IO getting > in the way. > > ----- > > I had to reduce to 100 iterations. > > On Linux: > > real 0m0.448s > user 0m0.244s > sys 0m0.220s > > On Cygwin: > > real 0m48.411s > user 0m15.005s > sys 0m18.520s > > So basically a factor of 100... again points to forking or Vista process > start slowness. I couldn't resist playing along at home on a Windows XP machine :) It doesn't seem to be just a Windows Vista problem: $ time for n in $(seq 1 10000); do /bin/true; done real 3m6.641s user 5m36.750s sys 1m49.580s $ time for n in $(seq 1 10000); do true; done real 0m0.453s user 0m0.421s sys 0m0.046s $ uname -a CYGWIN_NT-5.1 33LTLG 1.5.25(0.156/4/2) 2008-06-12 19:34 i686 Cygwin Lee -- 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