From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932119AbbC3Rpl (ORCPT ); Mon, 30 Mar 2015 13:45:41 -0400 Received: from one.firstfloor.org ([193.170.194.197]:47466 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753053AbbC3Rpf (ORCPT ); Mon, 30 Mar 2015 13:45:35 -0400 Date: Mon, 30 Mar 2015 19:45:33 +0200 From: Andi Kleen To: "Liang, Kan" Cc: Andi Kleen , Peter Zijlstra , "linux-kernel@vger.kernel.org" , "mingo@kernel.org" , "acme@infradead.org" , "eranian@google.com" Subject: Re: [PATCH V5 4/6] perf, x86: handle multiple records in PEBS buffer Message-ID: <20150330174533.GH2366@two.firstfloor.org> References: <1424701556-28270-1-git-send-email-kan.liang@intel.com> <1424701556-28270-5-git-send-email-kan.liang@intel.com> <20150330134531.GV23123@twins.programming.kicks-ass.net> <37D7C6CF3E00A74B8858931C1DB2F0770178BAF5@SHSMSX103.ccr.corp.intel.com> <20150330172545.GG2366@two.firstfloor.org> <37D7C6CF3E00A74B8858931C1DB2F0770178BC4D@SHSMSX103.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F0770178BC4D@SHSMSX103.ccr.corp.intel.com> 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 > > The case you mentioned has already covered in the description. AFAIK the description was for the "two PEBS events are happening nearby, so the hardware merges them" case. That is different than what I described. Both can happen (very rarely) > I tried both multiple different events and multiple same events. > As you said, the collision for multiple different events is rare. > The collision for multiple same events is very high, but it's not a useful > configuration > > As my understanding, Peter means the multiple PEBS bits could be set > when sampling only one single event. -Andi