From nobody Fri May 05 15:52:29 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 4QCZvP0hGFz49Tb0; Fri, 5 May 2023 15:52:33 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2]) (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 did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4QCZvN5R7rz43KD; Fri, 5 May 2023 15:52:32 +0000 (UTC) (envelope-from hps@selasky.org) Authentication-Results: mx1.freebsd.org; none Received: from [10.36.2.154] (unknown [46.212.121.255]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 8CADD260734; Fri, 5 May 2023 17:52:29 +0200 (CEST) Message-ID: <84816f2f-b23c-f448-55fe-454cbb604681@selasky.org> Date: Fri, 5 May 2023 17:52:29 +0200 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 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 Subject: Re: Support for more than 256 CPU cores To: Tomek CEDRO , Ed Maste Cc: freebsd-arch , FreeBSD Current References: Content-Language: en-US From: Hans Petter Selasky In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4QCZvN5R7rz43KD X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/32, country:DE] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N On 5/5/23 17:23, Tomek CEDRO wrote: > On Fri, May 5, 2023 at 3:38 PM Ed Maste wrote: >> 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’s >> lifetime. (..) > > Congratulations! :-) > > I am looking after AMD Threadripper with 64 cores 2 threads each that > will give 128 CPU to the system.. maybe this year I could afford that > beast then I will report back after testing :-) > > In upcoming years variations of RISC-V will provide unheard before > number of CPU in a single SoC (i.e. 1000 CPU) at amazing power > efficiency and I saw reports of prototype with 3 x SoC of this kind on > a single board :-) > > https://spectrum.ieee.org/risc-v-ai > Hi, Maybe it makes sense to cluster CPU's in logical groups somehow. Some synchronization mechanism like EPOCH() are O(N²) where N is the number of CPUs. Not in the read-case, but in the synchronize case. It depends a bit though. Currently EPOCH() is executed every kern.hz . --HPS