From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751762AbcEGINd (ORCPT ); Sat, 7 May 2016 04:13:33 -0400 Received: from www.linutronix.de ([62.245.132.108]:33384 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbcEGIN3 (ORCPT ); Sat, 7 May 2016 04:13:29 -0400 Date: Sat, 7 May 2016 10:11:33 +0200 (CEST) From: Thomas Gleixner To: Andi Kleen cc: Peter Zijlstra , acme@kernel.org, jolsa@kernel.org, linux-kernel@vger.kernel.org, Andi Kleen , x86@kernel.org Subject: Re: [UPDATED PATCH 01/10] x86: Add topology_max_smt_threads() In-Reply-To: <20160506172426.GW13997@two.firstfloor.org> Message-ID: References: <1462489447-31832-1-git-send-email-andi@firstfloor.org> <1462489447-31832-2-git-send-email-andi@firstfloor.org> <20160506101318.GV3430@twins.programming.kicks-ass.net> <20160506172426.GW13997@two.firstfloor.org> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 6 May 2016, Andi Kleen wrote: > For SMT specific workarounds it is useful to know if SMT is active > on any online CPU in the system. This currently requires a loop > over all online CPUs. > > Add a global variable that is updated with the maximum number > of smt threads on any CPU on online/offline, and use it for > topology_max_smt_threads() > > The single call is easier to use than a loop. > > Not exported to user space because user space already can use > the existing sibling interfaces to find this out. Reviewed-by: Thomas Gleixner