From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755243AbbJUOfg (ORCPT ); Wed, 21 Oct 2015 10:35:36 -0400 Received: from one.firstfloor.org ([193.170.194.197]:49323 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754785AbbJUOfd (ORCPT ); Wed, 21 Oct 2015 10:35:33 -0400 Date: Wed, 21 Oct 2015 16:35:31 +0200 From: Andi Kleen To: Peter Zijlstra Cc: Andi Kleen , acme@kernel.org, jolsa@kernel.org, linux-kernel@vger.kernel.org, Andi Kleen , stable@vger.kernel.org, Ingo Molnar Subject: Re: [PATCH 1/5] x86, perf: Fix LBR call stack save/restore Message-ID: <20151021143530.GM3533@two.firstfloor.org> References: <1445366797-30894-1-git-send-email-andi@firstfloor.org> <20151021131310.GE3604@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151021131310.GE3604@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Any idea who much more expensive that wrmsr() is compared to the rdmsr() > it replaces? I don't know. > > If its significant we could think about having this behaviour depend on > callstacks. This function is only used for callstacks, otherwise it uses the LBR reset path. -Andi -- ak@linux.intel.com -- Speaking for myself only.