From owner-freebsd-ppc@freebsd.org Sun Feb 14 15:57:23 2021 Return-Path: Delivered-To: freebsd-ppc@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id BED1F5333A5 for ; Sun, 14 Feb 2021 15:57:23 +0000 (UTC) (envelope-from bdragon@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (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 (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DdsLq4q1Pz3jjG for ; Sun, 14 Feb 2021 15:57:23 +0000 (UTC) (envelope-from bdragon@FreeBSD.org) Received: from auth1-smtp.messagingengine.com (auth1-smtp.messagingengine.com [66.111.4.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: bdragon/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 921F329CED for ; Sun, 14 Feb 2021 15:57:23 +0000 (UTC) (envelope-from bdragon@FreeBSD.org) Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailauth.nyi.internal (Postfix) with ESMTP id 1B5F827C005B for ; Sun, 14 Feb 2021 10:57:23 -0500 (EST) Received: from imap38 ([10.202.2.88]) by compute3.internal (MEProxy); Sun, 14 Feb 2021 10:57:23 -0500 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrieehgdekfecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecufghrlhcuvffnffculddutddmnecujfgurhepofgfgg fkjghffffhvffutgesthdtredtreerjeenucfhrhhomhepfdeurhgrnhguohhnuceuvghr ghhrvghnfdcuoegsughrrghgohhnsefhrhgvvgeuufffrdhorhhgqeenucggtffrrghtth gvrhhnpeehfeeutdetudeiveelueejvdevkeffteeiuddvudegvdefiefgudfguefhheei ueenucffohhmrghinhepfhhrvggvsghsugdrohhrghdpghgvnhhunhhigidrtghomhenuc evlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegsughrrghg ohhnodhmvghsmhhtphgruhhthhhpvghrshhonhgrlhhithihqddutdegvdefheekieegqd dukedutdekheduqdgsughrrghgohhnpeephfhrvggvuefuffdrohhrghesihhmrghprdgt tg X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id 8B7D4CA005D; Sun, 14 Feb 2021 10:57:22 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.5.0-alpha0-141-gf094924a34-fm-20210210.001-gf094924a Mime-Version: 1.0 Message-Id: <5e905bca-c62e-4f72-8f22-09ac384b9ae9@www.fastmail.com> In-Reply-To: References: <8348beb1-06f4-6b65-cf62-74c81dcf31f6@blastwave.org> Date: Sun, 14 Feb 2021 09:57:02 -0600 From: "Brandon Bergren" To: "FreeBSD PowerPC ML" Subject: =?UTF-8?Q?Re:_Test_of_FreeBSD-13.0-ALPHA3-powerpc-powerpc64-20210129-40c?= =?UTF-8?Q?b0344eb2-256214-disc1.iso.xz?= Content-Type: text/plain X-BeenThere: freebsd-ppc@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Porting FreeBSD to the PowerPC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Feb 2021 15:57:23 -0000 On Sun, Feb 14, 2021, at 12:31 AM, Dennis Clarke via freebsd-ppc wrote: > Performance is best described as terrible. I did fetch src.txz from > the releases directory : > https://download.freebsd.org/ftp/releases/powerpc/powerpc64/13.0-BETA2/ Yes, the clang compiler is known to be *much* slower than the old GCC. It's gigantic in comparison and some of the passes are a lot more computationally expensive. It's a nearly 100 meg dynamically-linked binary. > > Currently running a buildworld which appears that it will be some days > before that completes. This may actually be slower than a qemu instance > of FreeBSD-CURRENT on RISC-V. Yeah, it probably will. I don't currently test buildworld on anything older than POWER8, just because it's so much time investment to do so. > The Decrementer exception seen in December CURRENT no longer exists. > Seen here > https://beta.genunix.com/freebsd/ppc64/power_mac_quad_freebsd_13_current_17_dec_2020_fail.png Yep. That is the problem that https://cgit.freebsd.org/src/commit/sys/powerpc/aim?id=d26f2a50ff48dacd38ba358d658882d51f7bdbc4 fixes. > I want to dig into the smp issue if I can but at the moment I will await > for a full buildworld/buildkernel and then see where we are. > I believe most of the smp issue boils down to the timebase getting out of sync between processors and causing paradoxes in the scheduler. There are some algorithms there that really don't like the timebase moving backwards and it can cause stuff like scheduled timers to get lost, which manifests in processes hanging in syscalls and such. There is some background discussion in https://reviews.freebsd.org/D23376 and on the list about this. The basic solution is to rendezvous and have all processors initialize their timebase to a specific value and then wait for a broadcast from the boot processor to all enable it at the same time. Unfortunately, I have limited ability to work on this as my only SMP PowerMac is a dual G4, which works a bit differently than the G5s. Although I could certainly work on the G4 version of this problem. -- Brandon Bergren bdragon@FreeBSD.org