From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753845AbbAYP5V (ORCPT ); Sun, 25 Jan 2015 10:57:21 -0500 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:52953 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631AbbAYP5Q (ORCPT ); Sun, 25 Jan 2015 10:57:16 -0500 Date: Sun, 25 Jan 2015 15:56:52 +0000 From: Russell King - ARM Linux To: Felipe Balbi Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Tony Lindgren , Linux Kernel Mailing List , Ingo Molnar , Paul Mackerras , Linux OMAP Mailing List , Linux ARM Kernel Mailing List Subject: Re: perf not capturing stack traces Message-ID: <20150125155651.GB11502@n2100.arm.linux.org.uk> References: <20150123195128.GE26557@saruman.tx.rr.com> <20150123205959.GD3073@kernel.org> <20150123223745.GJ26557@saruman.tx.rr.com> <20150124151204.GF3073@kernel.org> <20150124222342.GA26941@saruman.tx.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150124222342.GA26941@saruman.tx.rr.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 24, 2015 at 04:23:42PM -0600, Felipe Balbi wrote: > yeah, I'll try a few older kernels, also see if I can reproduce on other > boards. Perf works for me with CONFIG_FRAME_POINTER=y, but that's only for kernel space, and for userspace where the programs have been built for ARM mode with frame pointers. The kernel may work without CONFIG_FRAME_POINTER set, but I've never tested that, and I'd suggest that (given my experience looking at oops dumps) it's not all that reliable. Lastly, userspace without frame pointers is pretty much hopeless. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: perf not capturing stack traces Date: Sun, 25 Jan 2015 15:56:52 +0000 Message-ID: <20150125155651.GB11502@n2100.arm.linux.org.uk> References: <20150123195128.GE26557@saruman.tx.rr.com> <20150123205959.GD3073@kernel.org> <20150123223745.GJ26557@saruman.tx.rr.com> <20150124151204.GF3073@kernel.org> <20150124222342.GA26941@saruman.tx.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150124222342.GA26941@saruman.tx.rr.com> Sender: linux-kernel-owner@vger.kernel.org To: Felipe Balbi Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Tony Lindgren , Linux Kernel Mailing List , Ingo Molnar , Paul Mackerras , Linux OMAP Mailing List , Linux ARM Kernel Mailing List List-Id: linux-omap@vger.kernel.org On Sat, Jan 24, 2015 at 04:23:42PM -0600, Felipe Balbi wrote: > yeah, I'll try a few older kernels, also see if I can reproduce on other > boards. Perf works for me with CONFIG_FRAME_POINTER=y, but that's only for kernel space, and for userspace where the programs have been built for ARM mode with frame pointers. The kernel may work without CONFIG_FRAME_POINTER set, but I've never tested that, and I'd suggest that (given my experience looking at oops dumps) it's not all that reliable. Lastly, userspace without frame pointers is pretty much hopeless. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Sun, 25 Jan 2015 15:56:52 +0000 Subject: perf not capturing stack traces In-Reply-To: <20150124222342.GA26941@saruman.tx.rr.com> References: <20150123195128.GE26557@saruman.tx.rr.com> <20150123205959.GD3073@kernel.org> <20150123223745.GJ26557@saruman.tx.rr.com> <20150124151204.GF3073@kernel.org> <20150124222342.GA26941@saruman.tx.rr.com> Message-ID: <20150125155651.GB11502@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Jan 24, 2015 at 04:23:42PM -0600, Felipe Balbi wrote: > yeah, I'll try a few older kernels, also see if I can reproduce on other > boards. Perf works for me with CONFIG_FRAME_POINTER=y, but that's only for kernel space, and for userspace where the programs have been built for ARM mode with frame pointers. The kernel may work without CONFIG_FRAME_POINTER set, but I've never tested that, and I'd suggest that (given my experience looking at oops dumps) it's not all that reliable. Lastly, userspace without frame pointers is pretty much hopeless. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.