From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754283AbaE3Hjz (ORCPT ); Fri, 30 May 2014 03:39:55 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:51163 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751782AbaE3Hjy (ORCPT ); Fri, 30 May 2014 03:39:54 -0400 Date: Fri, 30 May 2014 09:39:34 +0200 From: Peter Zijlstra To: Andi Kleen Cc: gleb@kernel.org, pbonzini@redhat.com, eranian@google.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Implement PEBS virtualization for Silvermont Message-ID: <20140530073934.GC20167@laptop.programming.kicks-ass.net> References: <1401412327-14810-1-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1401412327-14810-1-git-send-email-andi@firstfloor.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 29, 2014 at 06:12:03PM -0700, Andi Kleen wrote: > PEBS is very useful (e.g. enabling the more cycles:pp event or > memory profiling) Unfortunately it didn't work in virtualization, > which is becoming more and more common. > > This patch kit implements simple PEBS virtualization for KVM on Silvermont > CPUs. Silvermont does not have the leak problems that prevented successfull > PEBS virtualization earlier. Silvermont is such an underpowered thing, who in his right mind would run anything virt on it to further reduce performance?