From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262311AbVFIHDP (ORCPT ); Thu, 9 Jun 2005 03:03:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261468AbVFIHDP (ORCPT ); Thu, 9 Jun 2005 03:03:15 -0400 Received: from smtp203.mail.sc5.yahoo.com ([216.136.129.93]:62874 "HELO smtp203.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S262311AbVFIHDJ (ORCPT ); Thu, 9 Jun 2005 03:03:09 -0400 Subject: Re: How does 2.6 SMP scheduler assign runqueues to multi-cores? From: Nick Piggin To: helen monte Cc: lkml In-Reply-To: References: Content-Type: text/plain Date: Thu, 09 Jun 2005 17:03:04 +1000 Message-Id: <1118300584.10122.118.camel@npiggin-nld.site> Mime-Version: 1.0 X-Mailer: Evolution 2.0.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2005-06-09 at 06:32 +0000, helen monte wrote: > > > > > By the way, in an SMT/hyperthreading processor, does the latest > >kernel > > > > > version assign one run queue per physical CPU, or per virtual > >processor? > > > > > > > > > one run-queue per physical CPU > > > > > > No. Each logical processor has its own runqueue. > > How about muti-core? Does each core also have its own run queue? Does > anyone know how multi-core would work with SMT? Is it possible that they > work together? Is the following a possible scenario? : A node has two > processors, each processor has two cores, and each core has two "virtual > cores". And there are 8 run queues in total. > It is always one runqueue per virtual CPU, so dual core has 2 runqueues, and dual core with SMT has 4 runqueues. IBM and I believe Intel have chips that support SMT and have 2 cores. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com