From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 70454 invoked by alias); 13 Apr 2018 19:55:18 -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 70431 invoked by uid 89); 13 Apr 2018 19:55:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.2 spammy=who'd, whod, flat, Hx-spam-relays-external:ESMTPA X-HELO: vsmx012.vodafonemail.xion.oxcs.net Received: from vsmx012.vodafonemail.xion.oxcs.net (HELO vsmx012.vodafonemail.xion.oxcs.net) (153.92.174.90) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 13 Apr 2018 19:55:16 +0000 Received: from vsmx004.vodafonemail.xion.oxcs.net (unknown [192.168.75.198]) by mta-8-out.mta.xion.oxcs.net (Postfix) with ESMTP id E43C08CF4D7 for ; Fri, 13 Apr 2018 19:55:13 +0000 (UTC) Received: from Gertrud (unknown [91.47.59.44]) by mta-8-out.mta.xion.oxcs.net (Postfix) with ESMTPA id C0A9CCDF7A for ; Fri, 13 Apr 2018 19:55:11 +0000 (UTC) From: Achim Gratz To: cygwin@cygwin.com Subject: Re: More oddities with multiple processor groups References: <87in8xwre7.fsf@Rainer.invalid> Date: Fri, 13 Apr 2018 19:55:00 -0000 In-Reply-To: (Brian Inglis's message of "Fri, 13 Apr 2018 11:22:29 -0600") Message-ID: <87lgdq51b4.fsf@Rainer.invalid> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-VADE-STATUS: LEGIT X-SW-Source: 2018-04/txt/msg00157.txt.bz2 Brian Inglis writes: > Have you tried installing and running hwloc package to find out how it sees your > system? Yes. That is OK, but it doesn't change the fact that an application in Cygwin can see N processors, but then can't actually run on all of them. If Cygwin would switch the process to processor group aware state by default then my understanding is that at least the processor group would have to be explicitly selected for each thread, while on Linux the scheduler would eventually use all of the NUMA nodes unless the application tells it prefers different affinities. > If you run lstopo under X, you get a pretty diagram, but you can also run > lstopo-no-graphics aka hwloc-ls without X. Running "apropos hwloc" lists > commands you can use to manipulate the topology. I'll have that machine switched to "flat mode" which will result in a single processor group (still with two NUMA nodes, so things like MPI still know what to do). I have no actual use for the current topology and don't want to deal with the obvious complications, especially as I seem to be the only person who'd have them. If I can free up some time I will want to find out why top crashes, but for me that'l be the end of it if I even get that far. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Factory and User Sound Singles for Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#WaldorfSounds -- 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