From nobody Fri May 5 13:38:25 2023 X-Original-To: freebsd-current@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 4QCWww3vhHz49LNk; Fri, 5 May 2023 13:38:40 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: from mail-lj1-f178.google.com (mail-lj1-f178.google.com [209.85.208.178]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4QCWwv0yTDz3QW1; Fri, 5 May 2023 13:38:39 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Authentication-Results: mx1.freebsd.org; dkim=none; spf=pass (mx1.freebsd.org: domain of carpeddiem@gmail.com designates 209.85.208.178 as permitted sender) smtp.mailfrom=carpeddiem@gmail.com; dmarc=none Received: by mail-lj1-f178.google.com with SMTP id 38308e7fff4ca-2ac8d9399d5so1956231fa.1; Fri, 05 May 2023 06:38:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683293917; x=1685885917; h=content-transfer-encoding:to:subject:message-id:date:from :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=0a2yu3ZV/04YR7xugxE7nV5wxaL+v7kRUY7APxX/EXk=; b=fG4y/Q4Btgm58YSpCMkUvMdrHUFXZmuPGzQ8pH+Knok6L6nXLiCjpYKCLbf2l91Z++ r7UcOljBvfR0lH332IcfCuKhNttoZxdDCvxqhtMNy9flzmFoP2XkNLDZX0xKfjev7XFK sOoTsEWRmISE7ZyLAkCdSeYE7xHCh+STazFLinhSN7Rrs9uso6rNf1xbe+amOGjrT9Ub rhtObAgBSk55f7rIPUI5FLb8Q3dX/b6F+xVDysfte8SF5BJj6IC1Bf9nemt1tQAXFClm 7+58DSPtQBkeyHqmz+XFzLhIzYfw3xa+yMWK28WT1LbgsH7+F4ZAZIdLFFPiHR3waS9d rPPg== X-Gm-Message-State: AC+VfDxV8/w4/ErbJ1TkmPEea2C7AmO0WtBnZ6j/roDUJuOI49jhjPK6 kl880mfal1CpTavCqDVc6LS4pH7uagK+iBIPHXjQ1hJ8 X-Google-Smtp-Source: ACHHUZ4m0YfFys0UyVNmSoyQ8LUkbLnN6/XOUN9W2b5guGu9MVwxZJQ24s7iEK7Dk+AgDASMYqYAvfWW6qWO63fC4Y0= X-Received: by 2002:a2e:964c:0:b0:2a7:7259:9587 with SMTP id z12-20020a2e964c000000b002a772599587mr442581ljh.46.1683293916821; Fri, 05 May 2023 06:38:36 -0700 (PDT) List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 From: Ed Maste Date: Fri, 5 May 2023 09:38:25 -0400 Message-ID: Subject: Support for more than 256 CPU cores To: freebsd-arch , FreeBSD Current Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spamd-Result: default: False [1.17 / 15.00]; NEURAL_SPAM_SHORT(0.57)[0.572]; NEURAL_SPAM_LONG(0.52)[0.520]; FORGED_SENDER(0.30)[emaste@freebsd.org,carpeddiem@gmail.com]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; MIME_GOOD(-0.10)[text/plain]; NEURAL_SPAM_MEDIUM(0.07)[0.073]; MLMMJ_DEST(0.00)[freebsd-arch@freebsd.org,freebsd-current@freebsd.org]; MIME_TRACE(0.00)[0:+]; RWL_MAILSPIKE_POSSIBLE(0.00)[209.85.208.178:from]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; RCVD_IN_DNSWL_NONE(0.00)[209.85.208.178:from]; FREEMAIL_ENVFROM(0.00)[gmail.com]; R_DKIM_NA(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; TO_DN_ALL(0.00)[]; FROM_NEQ_ENVFROM(0.00)[emaste@freebsd.org,carpeddiem@gmail.com]; FREEFALL_USER(0.00)[carpeddiem]; ARC_NA(0.00)[]; BLOCKLISTDE_FAIL(0.00)[209.85.208.178:server fail]; FROM_HAS_DN(0.00)[]; RCVD_TLS_LAST(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DMARC_NA(0.00)[freebsd.org]; RCVD_COUNT_TWO(0.00)[2] X-Rspamd-Queue-Id: 4QCWwv0yTDz3QW1 X-Spamd-Bar: + X-ThisMailContainsUnwantedMimeParts: N FreeBSD supports up to 256 CPU cores in the default kernel configuration (on Tier-1 architectures). Systems with more than 256 cores are available now, and will become increasingly common over FreeBSD 14=E2=80=99= s lifetime. The FreeBSD Foundation is supporting the effort to increase MAXCPU, and PR269572[1] is open to track tasks and changes. As a project we have scalability work ahead of us to make best use of high core count machines, but at a minimum we should be able to boot a GENERIC kernel on such systems, and have an ABI for the FreeBSD 14 release that supports such a configuration. Some changes have already been committed in support of increased MAXCPU, including increasing MAX_APIC_ID (commit c8113dad7ed4) and a number of changes to reduce bloat (such as commits 42f722e721cd, e72f7ed43eef, 78cfa762ebf2 and 74ac712f72cf). The next step is to increase the maximum cpuset size for userland. I have this change open in review D39941[2] and an exp-run request in PR271213[3]. Following that the kernel change for increasing MAXCPU is in D36838[4]. Additional work on bloat reduction will continue after this change, and looking forward FreeBSD is going to need ongoing effort from the community and the FreeBSD Foundation to continue improving scalability. [1] https://bugs.freebsd.org/269572 [2] https://reviews.freebsd.org/D39941 [3] https://bugs.freebsd.org/271213 [4] https://reviews.freebsd.org/D36838