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 Message-ID: <42987F19.8070502@plausible.org> Date: Sat, 28 May 2005 07:24:25 -0700 From: Andy Ross User-Agent: Mozilla Thunderbird 1.0.2-6 (X11/20050513) MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: Serious performance problems (malloc related?) References: <4297A14B.9070409@plausible.org> <20050527234027.GA7522@trixie.casa.cgf.cx> <4297B572.9050200@plausible.org> <20050528005054.GB7522@trixie.casa.cgf.cx> <4297F984.3000800@plausible.org> <20050528061001.GA9254@trixie.casa.cgf.cx> In-Reply-To: <20050528061001.GA9254@trixie.casa.cgf.cx> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Christopher Faylor wrote: > Ok. I tried it. I did not notice anything like what you described. > I saw no indication that malloc was being called after the original > startup. Dunno, the STL vectors need to copy the new strings somewhere, certainly. Is the operator new pointed at something other than malloc? I suppose it's possible that there's some second-level allocation work being done inside the STL... > I saw consistent (implied) ~3 millisecond waits for disk reads. But as I noted in my original post: It's not waiting on the disk reads. Comment out the split() call and watch the delays disappear. Raw I/O speed in cygwin is comparable to mingw or MSVC. The overhead is due, somehow, to activity within/under split(). Other than allocation, that function doesn't do any meaningful library interaction that I can see (although Vaclav's suggestion about exception handling is a very good one...). I'll point out again: this isn't just an issue of poorly optimized code. Something is spending 93% of the time in this program doing literally nothing inside those odd delays; if you take the delays out, you get performance on par with what you see on other platforms. That indicates to me that this is a synchronization bug. I won't have a win32 box available to test with until after the weekend, though. I know you'd prefer that I spend my own time working on this, but like I said this really isn't my platform. I got involved trying to help out FlightGear users who are really being hurt by this issue. Andy -- 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/