From nobody Wed Mar 22 17:10:43 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 4PhZk03Gt9z414f2 for ; Wed, 22 Mar 2023 17:10:48 +0000 (UTC) (envelope-from freebsd-rwg@gndrsh.dnsmgr.net) Received: from gndrsh.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4PhZjz6lgFz3nb1 for ; Wed, 22 Mar 2023 17:10:47 +0000 (UTC) (envelope-from freebsd-rwg@gndrsh.dnsmgr.net) Authentication-Results: mx1.freebsd.org; none Received: from gndrsh.dnsmgr.net (localhost [127.0.0.1]) by gndrsh.dnsmgr.net (8.13.3/8.13.3) with ESMTP id 32MHAhYR047583; Wed, 22 Mar 2023 10:10:43 -0700 (PDT) (envelope-from freebsd-rwg@gndrsh.dnsmgr.net) Received: (from freebsd-rwg@localhost) by gndrsh.dnsmgr.net (8.13.3/8.13.3/Submit) id 32MHAhe9047582; Wed, 22 Mar 2023 10:10:43 -0700 (PDT) (envelope-from freebsd-rwg) From: "Rodney W. Grimes" Message-Id: <202303221710.32MHAhe9047582@gndrsh.dnsmgr.net> Subject: Re: Periodic rant about SCHED_ULE In-Reply-To: To: sgk@troutmask.apl.washington.edu Date: Wed, 22 Mar 2023 10:10:43 -0700 (PDT) CC: Mark Millard , George Mitchell , FreeBSD Hackers X-Mailer: ELM [version 2.4ME+ PL121h (25)] 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: 4PhZjz6lgFz3nb1 X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; TAGGED_RCPT(0.00)[freebsd]; ASN(0.00)[asn:13868, ipnet:69.59.192.0/19, 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. I dont even try ULE any more. I just used 4BSD, as did bde@freebsd.org, ULE seems to suck when your have interactive use and compute bound on the same box. I have seen interactive in the past take seconds to echo a command. IIRC ULE and zfs in a memory contrained environment dont play nicely togeather either. +1 on the return to 4BSD as the default scheduler -- Rod Grimes rgrimes@freebsd.org