Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752439AbbKJLJJ (ORCPT ); Tue, 10 Nov 2015 06:09:09 -0500 Received: from mail-pa0-f51.google.com ([209.85.220.51]:36816 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752173AbbKJLJI convert rfc822-to-8bit (ORCPT ); Tue, 10 Nov 2015 06:09:08 -0500 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.0 \(3094\)) Subject: Re: [V3 PATCH] arm64: remove redundant FRAME_POINTER kconfig option and force to select it From: yalin wang In-Reply-To: <20151110103752.GH21606@e104818-lin.cambridge.arm.com> Date: Tue, 10 Nov 2015 19:09:00 +0800 Cc: Yang Shi , Will Deacon , Mark Rutland , linaro-kernel@lists.linaro.org, LKML , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 8BIT Message-Id: <49B0431C-4FDA-45CB-82AF-FA010197118D@gmail.com> References: <1447092595-12644-1-git-send-email-yang.shi@linaro.org> <20151110103752.GH21606@e104818-lin.cambridge.arm.com> To: Catalin Marinas X-Mailer: Apple Mail (2.3094) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1429 Lines: 36 > On Nov 10, 2015, at 18:37, Catalin Marinas wrote: > > On Mon, Nov 09, 2015 at 10:09:55AM -0800, Yang Shi wrote: >> FRAME_POINTER is defined in lib/Kconfig.debug, it is unnecessary to redefine >> it in arch/arm64/Kconfig.debug. Actually, the one defined in arm64 directory >> is never used. > > That's not true since the arm64 definition seems to take precedence. > >> This adds a dependency on DEBUG_KERNEL for building with frame pointers. > > It doesn't because arm64 selects ARCH_WANT_FRAME_POINTERS. > >> ARM64 depends on frame pointer to get correct stack backtrace and need >> FRAME_POINTER kconfig option enabled all the time. >> However, currect implementation makes it could be disabled, so force it >> to be selected by ARM64. >> >> Signed-off-by: Yang Shi > > Patch applied but I changed the commit log slightly. Thanks. i have a question, why FRAME_POINTER config must be enabled ? and i see ARM arch can disable this config . if i don’t need stack trace dump and the software release is for final product , don’t need debug stack trace log . is it possible to disable it for performance reason ? Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/