X-Recipient: archive-cygwin AT delorie DOT com X-Spam-Check-By: sourceware.org Date: Thu, 3 Jun 2010 19:59:44 -0400 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: Cygwin Performance and stat() Message-ID: <20100603235944.GA12167@ednor.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com References: <20100530170747 DOT GA8605 AT ednor DOT casa DOT cgf DOT cx> <4C03D6C5 DOT 4050004 AT x-ray DOT at> <80373222dd5d43b134a5ede7036e7674 DOT squirrel AT www DOT webmail DOT wingert DOT org> <20100602080626 DOT GV16885 AT calimero DOT vinschen DOT de> <383c8b44a088dad09a0b77d3299feda7 DOT squirrel AT www DOT webmail DOT wingert DOT org> <20100602174848 DOT GA14172 AT ednor DOT casa DOT cgf DOT cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) 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 On Thu, Jun 03, 2010 at 10:35:55AM -0700, Christopher Wingert wrote: >Using strace I was able to look at some of the functions that are >enumerated by debugging calls. > >The trace below is done by ls.exe for each file (approximately 95k files @ >88 mSecs/file), approximately 40 mSecs are spent in lstat64() and another >47 mSecs are spent in getacl(). You're undoubtedly misinterpreting the timestamps in strace. They don't indicate the amount of time spent in anything. They are just timestamps. >So I would say a combination of duplicated functionality between the two >function calls and making the Virus Scanner run is causing some of the >performance issues in Cygwin. Caching file information has obvious problems. And proper cache handling is not exactly simple. >So if you account for the Virus Scan overhead (that the cygwin version >seems to trip, but the DOS version does not) and the cache, you could >probably get stat performance down to around 10 mSecs/file. DOS is still >around 178 uSecs/file, still 6x better. > >I have no idea why these methods are used to get file information (ie >open() vs. Win32 GetFileAttributes()). Can anyone point to the current >maintainer of the fhandler* files? You may be missing how this project is run. The current maintainers of everything read this mailing list. You don't need to contact anyone personally. Actually, this is typical of many open source projects. cgf -- 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