Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754168AbbGQVBK (ORCPT ); Fri, 17 Jul 2015 17:01:10 -0400 Received: from mail-wg0-f50.google.com ([74.125.82.50]:33754 "EHLO mail-wg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753502AbbGQVBI (ORCPT ); Fri, 17 Jul 2015 17:01:08 -0400 MIME-Version: 1.0 In-Reply-To: <20150717203315.GI7380@tassilo.jf.intel.com> References: <1435612935-24425-1-git-send-email-andi@firstfloor.org> <1435612935-24425-3-git-send-email-andi@firstfloor.org> <20150717200900.GE7380@tassilo.jf.intel.com> <20150717203315.GI7380@tassilo.jf.intel.com> Date: Fri, 17 Jul 2015 14:01:06 -0700 Message-ID: Subject: Re: [PATCH 3/3] x86, perf: Add PEBS frontend profiling for Skylake From: Stephane Eranian To: Andi Kleen Cc: Thomas Gleixner , Andi Kleen , Peter Zijlstra , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1111 Lines: 28 On Fri, Jul 17, 2015 at 1:33 PM, Andi Kleen wrote: > On Fri, Jul 17, 2015 at 10:11:28PM +0200, Thomas Gleixner wrote: >> On Fri, 17 Jul 2015, Andi Kleen wrote: >> >> > > I believe this mask of 0x3fff17 is wrong and should instead be >> > > 0x7fffff based on the description of the FRONTEND >> > > MSR I see in the SDM Table 18-54 (bit 0-22 are valid). Otherwise, some >> > > valid latency values may be rejected. >> > >> > No, my mask is correct. >> >> Provide a proper argument for that. Just claiming 'my mask is correct' >> definitely falls not into that category. > > Because I actually tested the code unlike you or Stephane. > > # wrmsr 0x3f7 0x3fff17 > # wrmsr 0x3f7 0x7fffff > wrmsr: CPU 0 cannot set MSR 0x000003f7 to 0x00000000007fffff > # Fair enough! But then, the SDM is misleading. It is not describing what's implemented for SKL. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/