From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Covington Subject: Re: [PATCH v2] arm64: Fix task tracing Date: Wed, 10 Apr 2013 09:12:04 -0400 Message-ID: <51656524.10708@codeaurora.org> References: <20130408153132.GQ17476@mudshark.cambridge.arm.com> <1365510814-21343-1-git-send-email-cov@codeaurora.org> <20130410114126.GB26992@mudshark.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:46827 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751423Ab3DJNMG (ORCPT ); Wed, 10 Apr 2013 09:12:06 -0400 In-Reply-To: <20130410114126.GB26992@mudshark.cambridge.arm.com> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Will Deacon Cc: Catalin Marinas , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-arm-msm@vger.kernel.org" Hi Will, On 04/10/2013 07:41 AM, Will Deacon wrote: > On Tue, Apr 09, 2013 at 01:33:34PM +0100, Christopher Covington wrote: >> For accurate accounting pass contextidr_thread_switch the prev >> task pointer, since cpu_switch_to has at that point changed the >> the stack pointer. >> >> Signed-off-by: Christopher Covington > > Thanks Christopher -- I assume that using prev did resolve your issues? Yes indeed. We're now able to see in simulation that if a userspace process uses 100% CPU, its thread ID, rather than what was usually some random kthread, gets written out most of the time. I donno if that meets your criteria for a "real" use case, but I hope it's at least sufficient testing of the code for now. Thanks, Christopher -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation. From mboxrd@z Thu Jan 1 00:00:00 1970 From: cov@codeaurora.org (Christopher Covington) Date: Wed, 10 Apr 2013 09:12:04 -0400 Subject: [PATCH v2] arm64: Fix task tracing In-Reply-To: <20130410114126.GB26992@mudshark.cambridge.arm.com> References: <20130408153132.GQ17476@mudshark.cambridge.arm.com> <1365510814-21343-1-git-send-email-cov@codeaurora.org> <20130410114126.GB26992@mudshark.cambridge.arm.com> Message-ID: <51656524.10708@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Will, On 04/10/2013 07:41 AM, Will Deacon wrote: > On Tue, Apr 09, 2013 at 01:33:34PM +0100, Christopher Covington wrote: >> For accurate accounting pass contextidr_thread_switch the prev >> task pointer, since cpu_switch_to has at that point changed the >> the stack pointer. >> >> Signed-off-by: Christopher Covington > > Thanks Christopher -- I assume that using prev did resolve your issues? Yes indeed. We're now able to see in simulation that if a userspace process uses 100% CPU, its thread ID, rather than what was usually some random kthread, gets written out most of the time. I donno if that meets your criteria for a "real" use case, but I hope it's at least sufficient testing of the code for now. Thanks, Christopher -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation.