From nobody Wed Mar 22 16:48:17 2023 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4PhZD96xz2z413G3 for ; Wed, 22 Mar 2023 16:48:25 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "troutmask", Issuer "troutmask" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4PhZD91dWlz3kpZ for ; Wed, 22 Mar 2023 16:48:25 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Authentication-Results: mx1.freebsd.org; none Received: from troutmask.apl.washington.edu (localhost [127.0.0.1]) by troutmask.apl.washington.edu (8.17.1/8.17.1) with ESMTPS id 32MGmHDW004065 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 22 Mar 2023 09:48:17 -0700 (PDT) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.17.1/8.17.1/Submit) id 32MGmH4O004064; Wed, 22 Mar 2023 09:48:17 -0700 (PDT) (envelope-from sgk) Date: Wed, 22 Mar 2023 09:48:17 -0700 From: Steve Kargl To: Mark Millard Cc: George Mitchell , FreeBSD Hackers Subject: Re: Periodic rant about SCHED_ULE Message-ID: Reply-To: sgk@troutmask.apl.washington.edu References: <44FB7EE7-295F-46B1-9128-945DCAC6E79E.ref@yahoo.com> <44FB7EE7-295F-46B1-9128-945DCAC6E79E@yahoo.com> List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <44FB7EE7-295F-46B1-9128-945DCAC6E79E@yahoo.com> X-Rspamd-Queue-Id: 4PhZD91dWlz3kpZ X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; TAGGED_RCPT(0.00)[freebsd]; ASN(0.00)[asn:73, ipnet:128.95.0.0/16, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N On Wed, Mar 22, 2023 at 09:20:27AM -0700, Mark Millard wrote: > > Giving folks a way to know they are repeating your tests > appropriately, could give interested folks a way to answer > their own questions. This has been an issue for years (and now stretching into decades). It is trivial to show the problem with any numerically intensive MPI program. I've done this a few times, and reported the issues. Search the mailing list archives, e.g., https://lists.freebsd.org/pipermail/freebsd-hackers/2008-October/026375.html It appears to be (or was) an issue with cpu affinity. Caveat: I haven't tested this in a long time. I simple use 4BSD. -- Steve