From owner-freebsd-virtualization@freebsd.org Wed Nov 7 00:15:20 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 AACC711062B7 for ; Wed, 7 Nov 2018 00:15:20 +0000 (UTC) (envelope-from freebsd-rwg@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.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 CCA8B77516 for ; Wed, 7 Nov 2018 00:15:19 +0000 (UTC) (envelope-from freebsd-rwg@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (localhost [127.0.0.1]) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3) with ESMTP id wA703JAA098311; Tue, 6 Nov 2018 16:03:19 -0800 (PST) (envelope-from freebsd-rwg@pdx.rh.CN85.dnsmgr.net) Received: (from freebsd-rwg@localhost) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3/Submit) id wA703H1Q098310; Tue, 6 Nov 2018 16:03:17 -0800 (PST) (envelope-from freebsd-rwg) From: "Rodney W. Grimes" Message-Id: <201811070003.wA703H1Q098310@pdx.rh.CN85.dnsmgr.net> Subject: Re: is there a vCPU hard limit for bhyve guests? In-Reply-To: <20181106172535.20e46ef6@desktop.local> To: tech-lists Date: Tue, 6 Nov 2018 16:03:17 -0800 (PST) CC: freebsd-virtualization@freebsd.org X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: CCA8B77516 X-Spamd-Result: default: False [2.19 / 200.00]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_SPAM_SHORT(0.51)[0.508,0]; NEURAL_HAM_LONG(-0.31)[-0.306,0]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; DMARC_NA(0.00)[dnsmgr.net]; AUTH_NA(1.00)[]; NEURAL_SPAM_MEDIUM(0.12)[0.120,0]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MX_GOOD(-0.01)[cached: pdx.rh.CN85.dnsmgr.net]; RCPT_COUNT_TWO(0.00)[2]; R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; ASN(0.00)[asn:13868, ipnet:69.59.192.0/19, country:US]; MID_RHS_MATCH_FROM(0.00)[]; IP_SCORE(-0.02)[country: US(-0.08)] X-Rspamd-Server: mx1.freebsd.org 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: Wed, 07 Nov 2018 00:15:20 -0000 > Hi, > > On a host with hw.ncpu=48 I tried to start a bhyve guest with -c 24 and > it failed to start. So I tried -c 16 and it starts and runs as > expected. Any more than -c 16 fails to run. > > Is a maximum of 16 vCPU hardwired somewhere, and if so, why? Is there a > way to overcome the limit? man bhyve Look at -c option, default is 1 max is 16. There is a compile time constant VM_MAXCPU, you can raise that to 20, then other problems come about that require more patching. Last time I played with this it failed above 16, I suspect some other places have had a bad derived constant using the assumption that 16 is the max. > thanks, > -- > J. > _______________________________________________ > 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" > -- Rod Grimes rgrimes@freebsd.org