From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45900) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dfmLN-0004tY-QE for qemu-devel@nongnu.org; Thu, 10 Aug 2017 08:13:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dfmLJ-0000VS-Q3 for qemu-devel@nongnu.org; Thu, 10 Aug 2017 08:13:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8772) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dfmLJ-0000V6-Jc for qemu-devel@nongnu.org; Thu, 10 Aug 2017 08:13:37 -0400 References: <1502359687-25370-1-git-send-email-tianyu.lan@intel.com> From: Paolo Bonzini Message-ID: Date: Thu, 10 Aug 2017 14:13:30 +0200 MIME-Version: 1.0 In-Reply-To: <1502359687-25370-1-git-send-email-tianyu.lan@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] x86: Increase max vcpu number to 352 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Lan Tianyu , qemu-devel@nongnu.org Cc: mst@redhat.com, rth@twiddle.net, ehabkost@redhat.com On 10/08/2017 12:08, Lan Tianyu wrote: > Intel Xeon phi chip will support 352 logical threads. For HPC > usage case, it will create a huge VM with vcpus number as same as host > cpus. This patch is to increase max vcpu number to 352. Even without Xeon Phi, a 24-core, 8-socket system (E7-8890 v4 for example) will have 384 physical CPUs. 288 was the biggest we could test at the time, but now that the 256 vCPU barrier has been broken I agree with going straight to 512. Paolo