From owner-freebsd-virtualization@freebsd.org Tue Nov 27 22:20:40 2018 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 684DD113D4D2 for ; Tue, 27 Nov 2018 22:20:40 +0000 (UTC) (envelope-from trentnthompson@gmail.com) Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id AC12E7205B for ; Tue, 27 Nov 2018 22:20:39 +0000 (UTC) (envelope-from trentnthompson@gmail.com) Received: by mail-pl1-x631.google.com with SMTP id z23so16310430plo.0 for ; Tue, 27 Nov 2018 14:20:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ugf37Qt/Hg57cCNvek0ulrW0xM7cNzH6dc9ZUnk2uT0=; b=sScR24PFUvrecfEZmi4haQ0DKuw8s7qkeu4pvQcCJj2PjTksGfZVjoxEAW1B9ut+2U AjVyJBwG8Uc+NQDSR5l4R5RBrmg/hzrnJygX6ZDc/iyHitts1o3iHBmyMsiifQ3vkjqE bYKhCNthu6zG9hrzijLEFEKO6nlU54tBAsUBY7dn21CIUv3E5VIwBbO9gsh/Au+t62X7 zSXy8PT+4sK5UTSDearveqPa6UdcbZ7sbPhD9dROMfbi/NgEkzAI2UuIPRhD3YywZ++2 1TkWp/N7y531cv69rr66WsuQQKaWDKPbqqwj9ekx6jWFsNlAQKkQseDJt58Sezad9J7s yoTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Ugf37Qt/Hg57cCNvek0ulrW0xM7cNzH6dc9ZUnk2uT0=; b=fyRdJYV+3myAmfWYp91/e2AQ1PqrHtgCGOY4JTyr/7cVj5PYPfIHU6lGW7P1mz1e/D EtgsbDNJ2zch1Gx0nrPK/nsZpTIbktyzD0ETdmyJWxCKaXnx44nzxr5jVvltRYdM5yMS xIBvkHkN0U/I+NW0Hl+iLrbMq0QCDCu5KmkZPu1qXc4vrxhu+rnKTnMtOFP2vksmWr8J aW6Qrf7wGK+U2xKvqBjYfFYFqD/ZipyPFVUWygtUjTXQ2tIyGezRe0FbUEPeuK8Y58ob YBJEG1CyKX+Ssmgu62y2LqR3sxSGHS81TA4BtqEEWQ9kXzyKMZzZMVef5TkY5tcutEIL WmpA== X-Gm-Message-State: AA+aEWZ+UHEXmNrJNg/tQxfY43NnAAhbZlO90A4XxwDVteU957RceGM3 Qu1/nmyKzLKg7J/Yl4NwbU1+y79QNnpD1HtDGyY= X-Google-Smtp-Source: AFSGD/V9c2AvWZ17spIqs9yh5DAZImc2koAIpbOFZRuquq/0pJznlt9bn8g6XJ8iLRS06OA5Q7VR1Y9sJQZQQ6T+Da8= X-Received: by 2002:a17:902:e18c:: with SMTP id cd12mr17826845plb.279.1543357238444; Tue, 27 Nov 2018 14:20:38 -0800 (PST) MIME-Version: 1.0 References: <331a93ae-d4d8-e510-4499-7185e31fbbc9@gmail.com> In-Reply-To: <331a93ae-d4d8-e510-4499-7185e31fbbc9@gmail.com> From: Trent Thompson Date: Tue, 27 Nov 2018 15:20:26 -0700 Message-ID: Subject: Re: Any plans to increase the maximum number of virtual CPUs above 16? To: Simon Connah Cc: FreeBSD virtualization X-Rspamd-Queue-Id: AC12E7205B X-Spamd-Result: default: False [-3.62 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; R_DKIM_ALLOW(-0.20)[gmail.com]; FROM_HAS_DN(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-virtualization@freebsd.org]; RCVD_IN_DNSWL_NONE(0.00)[1.3.6.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; RCPT_COUNT_TWO(0.00)[2]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; NEURAL_HAM_SHORT(-0.96)[-0.962,0]; SUBJECT_ENDS_QUESTION(1.00)[]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; RCVD_TLS_LAST(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; IP_SCORE(-0.65)[ipnet: 2607:f8b0::/32(-1.77), asn: 15169(-1.37), country: US(-0.09)] X-Rspamd-Server: mx1.freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Nov 2018 22:20:40 -0000 Simon, It is possible to go above that limit if you're willing to recompile the VMM kernel module. There has been some discussion as to why this was set to 16 recently ( https://lists.freebsd.org/pipermail/freebsd-virtualization/2018-November/006939.html ). Some may experience problems at higher counts. I had no issues at 32, and I believe someone else didn't have issues at 24. The line `#define VM_MAXCPU 16 /* maximum virtual cpus */` is what needs to be changed. Reference: https://lists.freebsd.org/pipermail/freebsd-virtualization/2016-September/004721.html On Tue, Nov 27, 2018, 3:07 PM Simon Connah I was reading the bhyve man page and noticed that it said the maximum > number of virtual CPUs is limited to 16. With AMD Epyc being out with 32 > cores and 64 threads per CPU and being able to have 2 of them in one > system this number seems rather low by modern standards. > > Are there any plans to increase this number to something like 32 virtual > CPUs? > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to " > freebsd-virtualization-unsubscribe@freebsd.org" >