Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966245AbbKFRvZ (ORCPT ); Fri, 6 Nov 2015 12:51:25 -0500 Received: from foss.arm.com ([217.140.101.70]:43282 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966227AbbKFRvY (ORCPT ); Fri, 6 Nov 2015 12:51:24 -0500 Date: Fri, 6 Nov 2015 17:51:20 +0000 From: Catalin Marinas To: "Shi, Yang" Cc: Mark Rutland , linaro-kernel@lists.linaro.org, Will Deacon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm64: remove redundant FRAME_POINTER kconfig option Message-ID: <20151106175119.GD7637@e104818-lin.cambridge.arm.com> References: <1446658671-16238-1-git-send-email-yang.shi@linaro.org> <20151106123008.GK6087@arm.com> <20151106125002.GA8116@leverpostej> <20151106162109.GZ7637@e104818-lin.cambridge.arm.com> <20151106162538.GU6087@arm.com> <563CE21A.6060803@linaro.org> <20151106173558.GC7637@e104818-lin.cambridge.arm.com> <563CE5BB.2080701@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <563CE5BB.2080701@linaro.org> 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 Content-Length: 1950 Lines: 57 On Fri, Nov 06, 2015 at 09:39:07AM -0800, Shi, Yang wrote: > On 11/6/2015 9:35 AM, Catalin Marinas wrote: > >On Fri, Nov 06, 2015 at 09:23:38AM -0800, Shi, Yang wrote: > >>On 11/6/2015 8:25 AM, Will Deacon wrote: > >>>However, the patch would allow one to > >>>disable FRAME_POINTERS (not sure it has any effect on the aarch64 gcc > >>>though). > >> > >>No, it doesn't. Actually, FRAME_POINTER could be disabled regardless of the > >>patch. > > > >In which case I suggest that we always select it just as a clearer > >statement that the feature cannot be disabled (and you never know what > >the compiler people decide to do in the future). > > Do you mean select FRAME_POINTER in ARCH_WANT_FRAME_POINTERS? > > Yes, we could, but this may cause other architectures which select > ARCH_WANT_FRAME_POINTERS to have FRAME_POINTER selected too. This would have been the ideal option, something like: --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -322,7 +322,7 @@ config ARCH_WANT_FRAME_POINTERS help config FRAME_POINTER - bool "Compile the kernel with frame pointers" + bool "Compile the kernel with frame pointers" if !ARCH_WANT_FRAME_POINTERS depends on DEBUG_KERNEL && \ (CRIS || M68K || FRV || UML || \ AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || \ But, as you said, we would need to check the other architectures selecting ARCH_WANT_FRAME_POINTERS. In the meantime: --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -27,6 +27,7 @@ config ARM64 select CPU_PM if (SUSPEND || CPU_IDLE) select DCACHE_WORD_ACCESS select EDAC_SUPPORT + select FRAME_POINTER select GENERIC_ALLOCATOR select GENERIC_CLOCKEVENTS select GENERIC_CLOCKEVENTS_BROADCAST -- Catalin -- 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/