From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.133]) by sourceware.org (Postfix) with ESMTPS id 43316385741B for ; Fri, 12 Nov 2021 09:41:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 43316385741B Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=cygwin.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=cygwin.com Received: from calimero.vinschen.de ([24.134.7.25]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.167]) with ESMTPSA (Nemesis) id 1N3bb1-1mcZ0O07Jj-010bSh for ; Fri, 12 Nov 2021 10:41:11 +0100 Received: by calimero.vinschen.de (Postfix, from userid 500) id 63EBAA80D4C; Fri, 12 Nov 2021 10:41:10 +0100 (CET) Date: Fri, 12 Nov 2021 10:41:10 +0100 From: Corinna Vinschen To: cygwin-developers@cygwin.com Subject: Re: timerfd question Message-ID: Reply-To: cygwin-developers@cygwin.com Mail-Followup-To: cygwin-developers@cygwin.com References: <02bf0670-ab2f-8bb2-a882-0ef8902bd791@cornell.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <02bf0670-ab2f-8bb2-a882-0ef8902bd791@cornell.edu> X-Provags-ID: V03:K1:VchbUUC/rY6dLlElZH+2eTvYewDkgvWdE1XyGCvbNkJghZqKQLg o69bPbrswp53pcmd+UkjrsvRbFoTdpM9PbLXFVhOKMNwZAjCcOxjqttGBUKAo7740AMepH3 n8hYiROXPjYZ/J5u7dbqP2f8xYZ9IJT7I8eJr2l8+rN35JAOJWsfFuM9p9Sc9WzkPb41Ras 4bQfBPwSwFB+nAAhgG+aA== X-UI-Out-Filterresults: notjunk:1;V03:K0:nYenAcWx1W0=:GRaIHpmefoV9Suvh2iM1YM 2/MdYk2ta9D6Qql6s1D/r7beLdVVvuUpU9jCPEKngizFN51zx7YXetIRzWvaD09s6VCadoa7j 5+fYJNH76s985frmxJr/ARTLoEyDbefP/TslX5TFx7/5zk+3dAhOzrtwJp05FLy6RCtn+NA/Q xrPe+uNgaHpBHTztQuIhA5YiMMv3tUN5jutRjkj7qykKtJx/7xIjB1aYj3k4BeiAN036LJsKp 0rJbfG34jqxLjPozRgMnRG/9AdZ3KsMdGpAwdLpYdi4dF0/SLjCWseM9sECyp55eyy7DgUI2+ BdbhXhUTNxoxWDh+/Luwp6liSheyHSw/a69RiGNLbJHI55ptyCi7+mka6ZyxKNc8jnnOg3d4J zQvlMzSk+10YIugpBTg+ZQS3u73dmnUQK0IAQ6plQ98pJp91T1vVmKDc1XU2j4/RXsRInsLm6 GZUI3yjo9EhG8EJ3R/4D7l12S0wYDwL1qunTKsfz/hLF0ZbgoMspXFONDcjBizKLXkl4S8QjL stu4LnGH59Dn78eRTjznUXUVg8akxBnsIRdin0ooHyiYx52YNockPGcrQXP/AcDx806aQMM1s 165HagHA6ddC3Okw0WFlehD4aH1ruklJak8BrFr1Ut4F4vfK94W30GxSNj+62nIps1jFNiV9L 2UnPDcJbvjkO7wAtUPoM4VNDgBjP+Ct6ARHZFjN0fkZJdvZyQ2eDTSq6wyslQXurXIP4Gxuvr if3R94o1vn/cCCyE X-Spam-Status: No, score=-99.1 required=5.0 tests=BAYES_00, GOOD_FROM_CORINNA_CYGWIN, JMQ_SPF_NEUTRAL, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NEUTRAL, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin-developers@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Cygwin core component developers mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Nov 2021 09:41:14 -0000 On Nov 11 17:52, Ken Brown wrote: > This question is almost certainly too vague to be answerable, but I'll try > anyway. Is there any obvious reason that it's bad to have two timers > running simultaneously, one using timerfd (started via timerfd_settime) and > one using a POSIX timer (started via timer_settime)? They don't share code, nor threads. I don't see a reason they should influence each other. Both are starting timers and handle them in independent threads. > Here's the context: Emacs runs timers. Until recently it used timerfd if > available, and otherwise a POSIX timer. After a recent change, it starts > both kinds of timers. This causes a severe slowdown on Cygwin > (https://debbugs.gnu.org/cgi/bugreport.cgi?bug=51734#32). The easiest thing > is just to disable that change on Cygwin, but I'd feel better understanding > why this is a problem. A STC might be helpful. Corinna