From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C4C4C433EF for ; Thu, 21 Oct 2021 12:28:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25D2260F59 for ; Thu, 21 Oct 2021 12:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231773AbhJUMbG (ORCPT ); Thu, 21 Oct 2021 08:31:06 -0400 Received: from linux.microsoft.com ([13.77.154.182]:49836 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231787AbhJUMbE (ORCPT ); Thu, 21 Oct 2021 08:31:04 -0400 Received: from [192.168.254.32] (unknown [47.187.212.181]) by linux.microsoft.com (Postfix) with ESMTPSA id CFC5B20B7179; Thu, 21 Oct 2021 05:28:47 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CFC5B20B7179 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1634819328; bh=DvHvI1eWTe/g+Ehqlznt9wtXs8WUeiscbm6lpSkMErM=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=YSvX7YSp4lwVxBlBM7o1zYZkCVrYuVhEO5iffMK7XhMMsFOtArvrvEjKUh+5fESNo ptiYAPdNHWleVi3nZ6fKVNDOMrm7hIzZHgZUfmnp4e6z1DTA407wINSW0a+ie7Ap9N UQU5dlSnzi/eWefqupMNyY/ubH+Ob5KgJbdV/K0Y= Subject: Re: [PATCH v10 02/11] arm64: Make perf_callchain_kernel() use arch_stack_walk() To: Mark Brown Cc: mark.rutland@arm.com, jpoimboe@redhat.com, ardb@kernel.org, nobuta.keiya@fujitsu.com, sjitindarsingh@gmail.com, catalin.marinas@arm.com, will@kernel.org, jmorris@namei.org, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org References: <20211015025847.17694-1-madvenka@linux.microsoft.com> <20211015025847.17694-3-madvenka@linux.microsoft.com> From: "Madhavan T. Venkataraman" Message-ID: Date: Thu, 21 Oct 2021 07:28:46 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On 10/20/21 9:59 AM, Mark Brown wrote: > On Thu, Oct 14, 2021 at 09:58:38PM -0500, madvenka@linux.microsoft.com wrote: >> From: "Madhavan T. Venkataraman" >> >> Currently, perf_callchain_kernel() in ARM64 code walks the stack using >> start_backtrace() and walk_stackframe(). Make it use arch_stack_walk() >> instead. This makes maintenance easier. > >> static bool callchain_trace(void *data, unsigned long pc) >> { >> struct perf_callchain_entry_ctx *entry = data; >> - perf_callchain_store(entry, pc); >> - return true; >> + return perf_callchain_store(entry, pc) == 0; >> } > > This changes us from unconditionally doing the whole walk to returning > an error if perf_callchain_store() returns an error so it's not quite a > straight transform, though since that seems like a useful improvement > which most likely on't have any practical impact that's fine. > > Reviewed-by: Mark Brown > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > Thanks. Madhavan