From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 760BBECF; Fri, 6 Dec 2024 04:29:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733459377; cv=none; b=M7qWtdkFpDlsUH5pWBjgE936b6X7Zq9c3ozcZlM5XJUofz8iduRhsx5iLzc+t4TrVeIFnC0RPUmYqbCkSo3MWIakr4AsX69Jje6lQyFCLrv3UBeXNotCl2LnG5sZuKtYfZgPq8oe+U7DLcVIiLJoKYbmNPAomHoESrYCEZDMnOY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733459377; c=relaxed/simple; bh=ACte4UBGSvGouCXSY/zdfbHLzl3Fi//YtS1Kb4ZbHDo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tuQKu/C2uLUau/vwogxrqTfU0aZEllp/GtPg3N64XBze3+23uVV3klqq5sQDqYutpv+sqsobwtyrnCA/B39MoLWK+PSrk61ph7IPWINTgKwceOt2BKKCeQmeuWSLgQWWfwwSXkdexXbTe1duOC59pETUx55qnKkNIbhVxpdekho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 A47F2169E; Thu, 5 Dec 2024 20:30:02 -0800 (PST) Received: from [10.163.50.12] (unknown [10.163.50.12]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BDAD13F58B; Thu, 5 Dec 2024 20:29:29 -0800 (PST) Message-ID: <03245d82-ad68-4ac2-a6f1-d8e4cc5397c3@arm.com> Date: Fri, 6 Dec 2024 09:59:27 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/4] arm64: introduce rodata=noalias To: Huang Shijie , catalin.marinas@arm.com, will@kernel.org Cc: patches@amperecomputing.com, paulmck@kernel.org, akpm@linux-foundation.org, thuth@redhat.com, rostedt@goodmis.org, xiongwei.song@windriver.com, ardb@kernel.org, steven.price@arm.com, suzuki.poulose@arm.com, mark.rutland@arm.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, cl@os.amperecomputing.com References: <20241126085647.4993-1-shijie@os.amperecomputing.com> <20241126085647.4993-4-shijie@os.amperecomputing.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20241126085647.4993-4-shijie@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/26/24 14:26, Huang Shijie wrote: > The rodata=noalias is the original rodata=on. > > The rodata=noalias can provide us more block mappings and contiguous hits > to map the linear region which minimize the TLB footprint. And the > linear aliases of pages belonging to read-only mappings in vmalloc > region are also marked as read-only. > > Also update kernel-parameters.txt for it: > change "full" to "noalias" > > Signed-off-by: Huang Shijie > --- > Documentation/admin-guide/kernel-parameters.txt | 2 +- > arch/arm64/include/asm/setup.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index dc663c0ca670..54b4df42e631 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -5894,7 +5894,7 @@ > rodata= [KNL,EARLY] > on Mark read-only kernel memory as read-only (default). > off Leave read-only kernel memory writable for debugging. > - full Mark read-only kernel memory and aliases as read-only > + noalias Use more block mappings,may have better performance. > [arm64] > > rockchip.usb_uart > diff --git a/arch/arm64/include/asm/setup.h b/arch/arm64/include/asm/setup.h > index 5ded3bd11476..3d96dde4d214 100644 > --- a/arch/arm64/include/asm/setup.h > +++ b/arch/arm64/include/asm/setup.h > @@ -31,7 +31,7 @@ static inline bool arch_parse_debug_rodata(char *arg) > return true; > } > > - if (!strcmp(arg, "full")) { > + if (!strcmp(arg, "noalias")) { > rodata_enabled = true; > rodata_full = false; > return true; This patch should be folded back into [PATCH 1/4] ensuring that - "rodata=" processing gets updated completely i.e dropping 'full', adding new 'noalias' and also updating the documentation at once - Avoids temporary the "full" option breakage as mentioned earlier Also please do add in code comment above arch_parse_debug_rodata() function explaining all the options after these update.