Received: by 2002:a25:b794:0:0:0:0:0 with SMTP id n20csp5273050ybh; Wed, 7 Aug 2019 03:33:07 -0700 (PDT) X-Google-Smtp-Source: APXvYqyoNlf1MdAUgHW8hf0LmLxqQNOAhkw9yFAGPjpLR9oIlO6iLtTd8XhPXurAMHNrFKtTW+r1 X-Received: by 2002:a17:90a:3086:: with SMTP id h6mr7927568pjb.14.1565173987606; Wed, 07 Aug 2019 03:33:07 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565173987; cv=none; d=google.com; s=arc-20160816; b=o/Z90Zh5cdf9VRadZTS5Z16yX8AB0vd3pLqwUDXHJRwjBiBVAPTxreZrmG+j5CM0Xs shAAAoxGCvPF5Casu7/+//bUJBjIcgIl1PspCXoUU67+bWwqq9sXas6lyzq5BFTwi56/ 1ThT7aiK/gA9S/eaNskmS3q124vYGb+g6Tr9iIslhuY665qLZkEpXtn4ynn0Pybn77KV GrQo3Usuurj79SdmqcdcNuyIBUEQ+nh5qMmCY+shsh3ZHsBR2hj3ZoWKkFoC1OxrBleb WNswty2McC1Xr9SFvPHZ0JYe8KqKr6/k4X9fYuvdjUAOKQP0YlisaoTtBy6cUolSWwPH LYcA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=y7VUT17Wess8phpigwz7wqDF4CECfro3CaqeowAV/gA=; b=MoCS6t4ExVjI4i+KQxbD1SQjxvEbNRHt7o26fYpOh1JmblWHaC+XXpByxiaRBMBOiK FGLCCI71VG5v8YwxIbFQcP1oQAg3JHaATDpU8Yv4NmZdvDNQN1zcjZ5BloPIl8u8sfNN hegg7o+NV6VBbLQco/+EyFDcMA7RKcaG+OXOdH0HqKFp1+1ZqOfOWUBeXZihi5YUVlIm V/XwgpV79HC1uvg2rZ0svIVu7DNrfeoTY7+Vq+zTY8OpQwLY1CyQ+3aKqRLomXDlSY9s n2uxxDtaCxCi2QsUo8fIMhBdJXua6++Foynk0TUR2ig1DGyCQHvGKlFyjI90OyJPyRIh 3LOA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h65si51266945pfe.216.2019.08.07.03.32.52; Wed, 07 Aug 2019 03:33:07 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728365AbfHGK3l (ORCPT + 99 others); Wed, 7 Aug 2019 06:29:41 -0400 Received: from foss.arm.com ([217.140.110.172]:46058 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727464AbfHGK3l (ORCPT ); Wed, 7 Aug 2019 06:29:41 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D7F0828; Wed, 7 Aug 2019 03:29:40 -0700 (PDT) Received: from arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D439A3F575; Wed, 7 Aug 2019 03:29:39 -0700 (PDT) Date: Wed, 7 Aug 2019 11:29:37 +0100 From: Dave Martin To: Nathan Huckleberry Cc: Tri Vo , linux@armlinux.org.uk, linux-kernel@vger.kernel.org, clang-built-linux , Robin Murphy , linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH] ARM: UNWINDER_FRAME_POINTER implementation for Clang Message-ID: <20190807102935.GE10425@arm.com> References: <20190801231046.105022-1-nhuck@google.com> <01222982-4206-9925-0482-639a79384451@arm.com> <20190805133940.GA10425@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 06, 2019 at 02:29:16PM -0700, Nathan Huckleberry wrote: > I'm not sure that we should disable a broken feature instead of > attempting a fix. > > CONFIG_FUNCTION_GRAPH_TRACER is dependent on CONFIG_FRAME_POINTER and > there have been reports by MediaTek that the frame pointer unwinder is > faster in some cases. Fair enough, just wanted to be sure we weren't doing something pointless. [...] Cheers ---Dave