From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2989 invoked by alias); 7 May 2017 03:47:44 -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 2960 invoked by uid 89); 7 May 2017 03:47:42 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-103.6 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,USER_IN_WHITELIST autolearn=ham version=3.3.2 spammy=Hx-languages-length:1959, her, H*Ad:U*reply-to-list-only-lh, H*UA:i686 X-HELO: pool-173-76-164-160.bstnma.fios.verizon.net Received: from localhost (HELO pool-173-76-164-160.bstnma.fios.verizon.net) (127.0.0.1) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 07 May 2017 03:47:40 +0000 Reply-To: cygwin@cygwin.com Subject: Re: cygserver - Postgres Multiple connection Load Testing - Inifinte Loop 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> <20170507032747.GA876495@rfd.leadboat.com> To: cygwin@cygwin.com From: "Larry Hall (Cygwin)" Message-ID: <590E98DD.9000805@cygwin.com> Date: Sun, 07 May 2017 04:01:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <20170507032747.GA876495@rfd.leadboat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2017-05/txt/msg00087.txt.bz2 On 05/06/2017 11:27 PM, Noah Misch wrote: > 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? Just FYI, Corinna is away for a bit (in European time, "a bit" = until June ;-) ) so don't be surprised if her response is delayed. -- Larry _____________________________________________________________________ A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting annoying in email? -- 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