X-Recipient: archive-cygwin AT delorie DOT com X-Spam-Check-By: sourceware.org Date: Thu, 3 Jun 2010 22:44:22 -0400 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: Cygwin Performance and stat() Message-ID: <20100604024422.GB12167@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> <20100603235944 DOT GA12167 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 05:32:46PM -0700, Christopher Wingert wrote: >> 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. > >Undoubtedly, no. > >I am doing basic subtraction based on the synchronous call made from >the ls.exe executable to the cygwin1.dll and the timestamp provided by >strace. Yeah, that's what I thought you were doing. Given that the timestamps don't indicate "elapsed time of function X", it's not always possible to figure out how long a function takes by subtracting. Subtracting timestamps shows the delta between one time that someone thought to put an strace_printf in the code and another time that someone thought to put an strace_printf in the code. There is no guarantee that there is an strace_printf at entry or exit of a function. It is a shame that we weren't more standardized in our strace output so that kind of thing could be possible. >>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. > >Actually it is atypical for core developers to monitor a high volume >generic question list such as this one, at least from my experience on >other open source projects. The core developers would leave it to some >nay-saying lackey. Well, for example, the core developers of gcc monitor the gcc mailing list which can have higher traffic than this one. Even the linux core developers monitor the list for interesting threads. Ditto freebsd developers. binutils developers monitor the binutils list. gdb developers monitor the gdb and gdb-patches mailing lists. I'd be surprised if there was a popular free software project with a high volume mailing list where a core developer would be willing to have private conversations with people who don't know the code base well. However, for Cygwin, the web site says multiple times in multiple places that you shouldn't send private email and to use the mailing list. So, other projects aside that really is how we do things here. Oh, and it isn't clear if you're implying that I'm a lackey but I'm really not. 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