From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757660AbdKOL0y (ORCPT ); Wed, 15 Nov 2017 06:26:54 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:55902 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756957AbdKOL0q (ORCPT ); Wed, 15 Nov 2017 06:26:46 -0500 Date: Wed, 15 Nov 2017 11:26:34 +0000 From: Russell King - ARM Linux To: Maninder Singh Cc: "mingo@kernel.org" , "will.deacon@arm.com" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , PANKAJ MISHRA , AMIT SAHRAWAT , Vaneet Narang Subject: Re: [PATCH 1/1] arm/stacktrace: stop unwinding after an invalid address. Message-ID: <20171115112634.GD31757@n2100.armlinux.org.uk> References: <20171024115338.GF20805@n2100.armlinux.org.uk> <1508845602-33508-1-git-send-email-maninder1.s@samsung.com> <20171115110922epcms5p28a7a3bdf40777fe5852c7d5bd08ec7a4@epcms5p2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171115110922epcms5p28a7a3bdf40777fe5852c7d5bd08ec7a4@epcms5p2> 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 Wed, Nov 15, 2017 at 11:09:22AM +0000, Maninder Singh wrote: > Hi Russell, > > >On Tue, Oct 24, 2017 at 05:16:42PM +0530, Maninder Singh wrote: > >> This patch stops unwinding backtrace in case of below 2 cases. > >> > >> (Issue observed while porting stackdepot on ARM, duplicate > >> entries created in stackdepot > >> reference patch for workaround in stackdepot:- > >> https://lkml.org/lkml/2017/10/11/353 > >> ). > >> > >> 1. If address belongs to irq/exception code, ignore it. > >> save_stack+0x40/0xec > >> __set_page_owner+0x2c/0x64 > >> .... > >> .... > >> __handle_domain_irq+0x9c/0x130 > >> gic_handle_irq+0x40/0x80 > >> __irq_usr+0x4c/0x60 > >> 0xb6507818 > >> ^^^^^^^ > > > >However, we _do_ want to trace through an IRQ taken in SVC mode, but you > >completely remove all that code. So, not taking this patch, sorry. > > OK. Thanks. > > But can we add some marker to distinguish before and after interrupt context frames. > so that we can remove interrupt that frames from stackdepot, because due to interrupt allocations, > we end up with so many stackdepot entries and which results in more memory consumption by stackdepot. Notice that I said "taken in SVC mode" not "taken in user mode". Your example below is for a user mode interrupt. > Something like below: > __set_page_owner+0x2c/0x64 > ... > ... > __handle_domain_irq+0x9c/0x130 > gic_handle_irq+0x40/0x80 > __irq_usr+0x4c/0x60 > 0xFFFFFFFF (marker) > 0xb6507818 > .... > > > Thus in stackdepot we can save before 0xFFFFFFF. > or can you provide any suggestion for the same if we can try for? -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up