Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752152AbdFOXST (ORCPT ); Thu, 15 Jun 2017 19:18:19 -0400 Received: from mga11.intel.com ([192.55.52.93]:21172 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751546AbdFOXSS (ORCPT ); Thu, 15 Jun 2017 19:18:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,345,1493708400"; d="scan'208";a="1141738526" Date: Thu, 15 Jun 2017 16:18:16 -0700 From: Andi Kleen To: Stephane Eranian Cc: LKML , Arnaldo Carvalho de Melo , Peter Zijlstra , "mingo@elte.hu" , "Liang, Kan" , Jiri Olsa Subject: Re: [PATCH 0/5] perf: add support for capturing skid IP Message-ID: <20170615231816.GD4789@tassilo.jf.intel.com> References: <1497534989-29231-1-git-send-email-eranian@google.com> <20170615151018.GA4789@tassilo.jf.intel.com> <20170615172320.GB4789@tassilo.jf.intel.com> <20170615200205.GC4789@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 415 Lines: 10 > Looking at this approach, the user interface is straightforward, > implementation in the x86 code is a bit more hairy because of the way > the branch_stack is captured, via the cpuc->lbr_entries. If you assume > that SKID_IP cannot be used with any other branch stack mode, then it > is easy. It becomes messy if you don't. That should be fine. After all if you have real LBRs you don't need the skid IP. -Andi