X-Spam-Check-By: sourceware.org Message-ID: <449228DE.206@cygwin.com> Date: Thu, 15 Jun 2006 23:43:26 -0400 From: "Larry Hall (Cygwin)" Reply-To: cygwin AT cygwin DOT com User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8) Gecko/20060112 Fedora/1.5-1.fc4.remi Thunderbird/1.5 Mnenhy/0.7.4.0 MIME-Version: 1.0 To: cygwin AT cygwin DOT com Subject: Re: random "fork: Resource temporarily unavailable" References: <4491D9B9 DOT 8010601 AT tlinx DOT org> In-Reply-To: <4491D9B9.8010601@tlinx.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm 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 Linda Walsh wrote: > I've not seen this message except when I've had to rapidly > press ^C to break out of a loop shell script. > > Today, I've seen it twice when there was virtually no cpu load > on the system, about 50% virtual memory committed, and 40 processes. > > Once, was with an "ls" command, the other happened as my shell was > starting up by some command invoked in the .rc script. > > I get suspicious whenever I see behavior on my computers when > anomalies crop up. > > I don't think any of my cygwin libraries have been updated recently. > > What would cause something like this? Memory fragmentation? > Insufficient real memory to "immediately" fork? I.e. I wonder > if, when NT goes to "fork", if it doesn't have enough free > memory, it tells the caller it failed (try again later) and > then starts a memory cleanup cycle to free up memory: i.e. rather > than the forking process sleeping while memory is made available > NT returns it immediately with a failure. > > Any idea on causes? Is it as rare as it has been for me? > A possible solution would be retry the fork a second time, or > sleep for a millisecond and then try fork again. I'm not sure, > but I think many *ixy (*='un'|'pos'|'lin'|'ir'...etc) type programs > may not retry the fork but immediately die, as on *ixy systems, > a fork failure is less common, and usually only happens when > the system really is out of resources. If that's the case, > it _might_ be an aid to smooth *ixy compatibility for the > library handling fork, retry the fork (possibly with millisecond > sleep) once before returning failure to the application. > > Not a high priority issue, but just wondering.... > > Linda > If it is NT returning failure rather than > forking, I wonder if, in order to provide a better "run-time" If you can reproduce this problem, I would suggest trying it again with a recent snapshot. -- Larry Hall http://www.rfk.com RFK Partners, Inc. (508) 893-9779 - RFK Office 838 Washington Street (508) 893-9889 - FAX Holliston, MA 01746 -- 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/