From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: oprofile and ARM A9 hardware counter Date: Tue, 3 Apr 2012 10:47:49 +0100 Message-ID: <20120403094749.GH17741@mudshark.cambridge.arm.com> References: <20120109224945.GA23090@mudshark.cambridge.arm.com> <20120403092524.GD17741@mudshark.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:55225 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751429Ab2DCJsH (ORCPT ); Tue, 3 Apr 2012 05:48:07 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Shilimkar, Santosh" Cc: Ming Lei , "eranian@gmail.com" , Maynard Johnson , Lik Lik , "oprofile-list@lists.sourceforge.net" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "Cousson, Benoit" , Paul Walmsley On Tue, Apr 03, 2012 at 10:42:30AM +0100, Shilimkar, Santosh wrote: > On Tue, Apr 3, 2012 at 2:55 PM, Will Deacon wrote: > > Did you ever get to the bottom of this? This change really is required in > > order to generate PMU interrupts with the CTI and I don't know of any > > alternative to the above. > > > > Any suggestions? > > > Sorry I lost track of this one. There is one relevant patch in Kevin's queue > for 3.4/fixes. [1] which I generated for perf time stamp issue. Thanks, I'll take a look. > Can you try that patch and see if it helps the CTI issue as well ? There > is an outside chance that it might help. If it doesn't, we should commit > Ming Lei patch. It seems that they're both needed to get reliable PMU operation. Without the CLKDM_CAN_SWSUP fix, no interrupts are generated at all. Without the patch below ([1]), it seems that we don't generate enough. So it looks like we need them both. > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2012-March/089679.html Cheers, Will