Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm 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 Date: Sat, 26 Jun 2004 12:05:54 -0400 From: "Pierre A. Humblet" To: cygwin@cygwin.com Subject: Re: higher-level IO very slow with cygwin1.dll 5.10 (due to set_flags?) Message-ID: <20040626160554.GA980221@hpn5170x> Mail-Followup-To: "Pierre A. Humblet" , cygwin@cygwin.com References: <20040626154504.GA961349@hpn5170x> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040626154504.GA961349@hpn5170x> User-Agent: Mutt/1.4.1i On Sat, Jun 26, 2004 at 11:45:04AM -0400, Pierre A. Humblet wrote: > On Sat, Jun 26, 2004 at 02:36:52AM -0400, Joseph wrote: > > Thanks to those who responded to my post. > > > > I am not sure though if all of you read the > > entire sequence of the thread. > > > > In my first post, I did attach an excerpt > > from an strace dump of a sample program that > > seemed to show "where the time is going". > > You initial accusation against set_flags was unfounded > and led nowhere. But you have a very good point. > > Your "fast" program is doing reads in blocks of 1024. > Your "slow" program is using getc. > > I observed that the slow program was 20 times slower > than the fast one, even though strace showed that getc > was properly calling read in blocks of 1024. > > I then noticed that getc is not implemented as a macro > on Cygwin. It's a newlib function As you seem to care about a 20x speed increase, you can regain the speed by editing stdio.h, letting getc be a macro on Cygwin. Beware, I found this: 2000-05-19 DJ Delorie * libc/include/stdio.h: no getc/putc macros for cygwin; causes compatibility issues with different dll versions so you may need to recompile when updating cygwin. Pierre -- 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/