From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 118979 invoked by alias); 7 May 2017 03:27:53 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 118944 invoked by uid 89); 7 May 2017 03:27:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 spammy=symptoms, render, sixteen, smoothly X-HELO: mail-pf0-f175.google.com Received: from mail-pf0-f175.google.com (HELO mail-pf0-f175.google.com) (209.85.192.175) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 07 May 2017 03:27:49 +0000 Received: by mail-pf0-f175.google.com with SMTP id q20so18641203pfg.0 for ; Sat, 06 May 2017 20:27:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=BTtu/dyQn1YQ4tdri7OMw0T2DoytnjvyM8lH9/UHMsA=; b=ougFNDgPR4zgxGp0iAIBBof6dq96ryDISGeyVLIHmezrmEjFUGUJUTP1Xp4QQ9K0Sy S2ahJwGV+LHgsAbVHs8U2qlgDTod5V5J5YeUl+CcBals1bFKmZhzh3SacooE9DNuxb2X drc62WiQivzrCc6at6tPXXNGhKoGaoIhWm0kKJxtXS3CnizZKLK8pvVyzPAk4wuPsMcK kZMRPuMKc29qzmam6mokTDmdOV0vUBFfrU+3U/x7HNX7JlO1Vbz6oMxlHZI+HPSQ10eR iIvUebchcP6oOrZX9RIzmzf0OsX6k2L2HIClvE497LG6liVFTV89IXecDNQ9PuSqM/Xs huNA== X-Gm-Message-State: AN3rC/5IC1uAVcjihQP7ld4/AxL1dfyBzqUNwKBEwHBor7BTemAlkvRi qPs7hBycdhBm4d6JHDjq3g== X-Received: by 10.99.128.72 with SMTP id j69mr11562634pgd.28.1494127670600; Sat, 06 May 2017 20:27:50 -0700 (PDT) Received: from rfd.leadboat.com (c-98-248-47-228.hsd1.ca.comcast.net. [98.248.47.228]) by smtp.gmail.com with ESMTPSA id p3sm10335369pgd.36.2017.05.06.20.27.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 06 May 2017 20:27:49 -0700 (PDT) Date: Sun, 07 May 2017 03:35:00 -0000 From: Noah Misch To: cygwin@cygwin.com Subject: Re: cygserver - Postgres Multiple connection Load Testing - Inifinte Loop Message-ID: <20170507032747.GA876495@rfd.leadboat.com> References: <200408030333.i733XEXn023894@mx3.redhat.com> <20040803100612.GP31522@cygbert.vinschen.de> <20170321025614.GA2100214@tornado.leadboat.com> <20170324171101.GI29995@calimero.vinschen.de> <20170328052652.GA2351961@tornado.leadboat.com> <20170402023624.GA2561924@tornado.leadboat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170402023624.GA2561924@tornado.leadboat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-SW-Source: 2017-05/txt/msg00085.txt.bz2 On Sat, Apr 01, 2017 at 10:36:24PM -0400, Noah Misch wrote: > On Tue, Mar 28, 2017 at 01:26:52AM -0400, Noah Misch wrote: > > On Fri, Mar 24, 2017 at 06:11:01PM +0100, Corinna Vinschen wrote: > > > I pushed a patchset now, and uploaded new developer snapshots for > > > testing to https://cygwin.com/snapshots/ > > > > > Please give it a try > > > I call the cygwin-20170324 freezes "limited" because the symptoms differ from > > the classic freeze I described upthread. "strace /bin/true" and "cat > > /proc/sysvipc/sem" do not hang, but every PostgreSQL backend process is stuck > > waiting on a synchronization primitive. > > > > I can distill another self-contained test case for the limited freeze seen in > > cygwin-20170324, but that make take awhile. I'm sending this early report so > > you're aware of the possible regression in cygwin-20170324. > > I'm attaching a new test program that demonstrates the regression. My previous > test program created sixteen processes that each picked a random semaphore to > lock. Now, each process picks two semaphores and locks them in order. This > proceeds smoothly on GNU/Linux and on cygwin-20170321.tar.xz "cygserver -r 40". > It freezes within one second on cygwin-20170324.tar.xz "cygserver -r 40". I suggest reverting the cygwin-20170324 cygserver changes for now. Older versions can be configured to have reliable sysv semaphores, but I think no settings render sysv semaphores reliable in Cygwin 2.8.0. What do you think? -- 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