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 46DF0C433FE for ; Fri, 1 Oct 2021 11:59:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2FA5D61ABC for ; Fri, 1 Oct 2021 11:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354197AbhJAMBm (ORCPT ); Fri, 1 Oct 2021 08:01:42 -0400 Received: from mail-vs1-f42.google.com ([209.85.217.42]:37424 "EHLO mail-vs1-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230510AbhJAMBl (ORCPT ); Fri, 1 Oct 2021 08:01:41 -0400 Received: by mail-vs1-f42.google.com with SMTP id f2so10080626vsj.4; Fri, 01 Oct 2021 04:59:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WR3+MFp1ibU3x0ZkDpZ824RbuuABr+gcaM86vEqsRNo=; b=BRh0WV659CFjH7+kssWg1sAcI9VqDTEcTsFY/uFEZGBqu8/7+TuPXPinTIa1/wJrnS iaiez80AjRm92GWRM12qn63IJbZWUGT0/w3QUZfF/LoPpHlu7AptnSbeGqx7+OzRfDiq vd84ZzWCt2JSrUYQI8GfWXfJmeDIGDU/2c8+qhAd6UvHDFFhz6Jv3ylVr9znvDop++J5 NOOuGU2OGRtbpPd/1ZPSaW6WlpmNkjzv9sAZ2y37s4b5seSmb3yqu9nyJAt/GVjhXjI2 xOvbBq4ekPSAQbKG3E2xUx5wbbdIkzlhmhLs39t4PKwsdamsWbcUDmlYomyKH1M6cYou UR3w== X-Gm-Message-State: AOAM532SJsWlWQWH3XCjBJyJ+ckkJqC43di0zIo8UqKsqo5CnnhP+44f Q0rjRhKskBdTAkGHK7jnL2gFKcvhb/Vn2R1VGIeDsmsBGiY= X-Google-Smtp-Source: ABdhPJyx7zg5kQJYsNSRRoL0YNyux79qxJGzafd5NYmhZJ2xCJLygfQPVXUiK/lmOsYXRavGy+aJ1Mf8eL4lb+ZaszY= X-Received: by 2002:a67:c295:: with SMTP id k21mr790199vsj.37.1633089597139; Fri, 01 Oct 2021 04:59:57 -0700 (PDT) MIME-Version: 1.0 References: <20210928235635.1348330-1-willmcvicker@google.com> <7766faf8-2dd1-6525-3b9a-8ba790c29cff@canonical.com> In-Reply-To: From: Geert Uytterhoeven Date: Fri, 1 Oct 2021 13:59:45 +0200 Message-ID: Subject: Re: [PATCH v2 00/12] arm64: Kconfig: Update ARCH_EXYNOS select configs To: Olof Johansson Cc: Saravana Kannan , Will McVicker , Krzysztof Kozlowski , Russell King , Catalin Marinas , Will Deacon , Michael Turquette , Stephen Boyd , Sylwester Nawrocki , Tomasz Figa , Chanwoo Choi , Linus Walleij , Alessandro Zummo , Alexandre Belloni , John Stultz , Thomas Gleixner , Lee Jones , "Cc: Android Kernel" , Linux ARM , Linux Kernel Mailing List , linux-samsung-soc , linux-clk , "open list:GPIO SUBSYSTEM" , linux-rtc@vger.kernel.org, Arnd Bergmann Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hi Olof, On Fri, Oct 1, 2021 at 7:36 AM Olof Johansson wrote: > A much more valuable approach would be to work towards being able to > free up memory by un-probed drivers at the end of boot. That would > possibly benefit all platforms on all architectures. We used to have such a functionality in arch/ppc (not arch/powerpc!), where code/data could be tagged __prep, __chrp, or __pmac, to put it in a special section, and to be freed with initdata when unused. It was removed in v2.6.15[1], as the savings weren't worth the hassle. In a more fragmented space like arm the memory lost due to alignment of the sections would be even more substantial. Another problem is to know when is the end of the boot, especially with deferred probing. [1] 6c45ab992e4299c8 ("[PATCH] powerpc: Remove section free() and linker script bits") Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds 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 1E109C433F5 for ; Fri, 1 Oct 2021 12:03:50 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D8BA161A85 for ; Fri, 1 Oct 2021 12:03:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D8BA161A85 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2LPrKXtJ/03JkYDyO5JBnT1l1wbpED6XYSvD2Z2Fg9g=; b=gjyZ8wRNxVYqCp mlL/8eCTWa3FRh8J23th1C9ACxYzxDeLWbzbB07HCr674GyBO0i0tjpQdmilylVFiMarvchMxJPyP YFg0yy05U91ThJ7GX+Z51SOXNBKaDB8B4zU3sW5zw+JYpcB2IwM9dGyKUZRHz/7+3r7j/7vR7ETpB HtwHyfkUx6n2dWTmXYTzLYc0GBljoq4zxBtnH+Uc5NZj1UHq2BBwYFu4qni2A/8PnkHjoms+PUe+j X9f4yVphkAHqlXEYu7B9DZ9aa4glq9vQL1uMYwD+/KFhGrWSSY11eT0QhZowk8ZldNRg0ZjVpAXgv MH9C4U8yhM7OZd9aqQPw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mWHDu-0004wH-VC; Fri, 01 Oct 2021 12:01:07 +0000 Received: from mail-vs1-f48.google.com ([209.85.217.48]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mWHCo-0004KS-VO for linux-arm-kernel@lists.infradead.org; Fri, 01 Oct 2021 12:00:01 +0000 Received: by mail-vs1-f48.google.com with SMTP id x1so10948628vsp.12 for ; Fri, 01 Oct 2021 04:59:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WR3+MFp1ibU3x0ZkDpZ824RbuuABr+gcaM86vEqsRNo=; b=ENF/DS1xZGbG67pMNWlOmznj+OiExcCrnvuCMZhYoCM8v0jhEKqrLvH3WF/Q7Yj8CD LpXvNk4pEMNvnsSjGav9UguQ5c1G1RoNZezkBAOzfwFCR2WzYO5iqo7/BC5lZn2BSPvu xebaxD80b3RdV1yrC/ffkclPpi/fjhaoLRb+FUg7fqKQ/D3ryC4UseXmKltdi8RwDx9h rQQI27CtxS3a77yOE/Cyw34oSwEu+ej4qC/zlesAwGJ8fKpPNi7JYv8fJDqwNxjlfsSM k8cPFPl8qOsjWWQx2AXV4ZDMzL0g+iLS0j8FDlGbCKobAcz4x/pKmwN2uP099Jr8kU2Y J3MQ== X-Gm-Message-State: AOAM530L7Lu02e4URYOqkFquCWWdAQXMG4r4bg6YLyOTwRjYun8+1HH2 bJJ6C4FVKirKkGbOjW6PVgLr9s43loHMgqgUGOY= X-Google-Smtp-Source: ABdhPJyx7zg5kQJYsNSRRoL0YNyux79qxJGzafd5NYmhZJ2xCJLygfQPVXUiK/lmOsYXRavGy+aJ1Mf8eL4lb+ZaszY= X-Received: by 2002:a67:c295:: with SMTP id k21mr790199vsj.37.1633089597139; Fri, 01 Oct 2021 04:59:57 -0700 (PDT) MIME-Version: 1.0 References: <20210928235635.1348330-1-willmcvicker@google.com> <7766faf8-2dd1-6525-3b9a-8ba790c29cff@canonical.com> In-Reply-To: From: Geert Uytterhoeven Date: Fri, 1 Oct 2021 13:59:45 +0200 Message-ID: Subject: Re: [PATCH v2 00/12] arm64: Kconfig: Update ARCH_EXYNOS select configs To: Olof Johansson Cc: Saravana Kannan , Will McVicker , Krzysztof Kozlowski , Russell King , Catalin Marinas , Will Deacon , Michael Turquette , Stephen Boyd , Sylwester Nawrocki , Tomasz Figa , Chanwoo Choi , Linus Walleij , Alessandro Zummo , Alexandre Belloni , John Stultz , Thomas Gleixner , Lee Jones , "Cc: Android Kernel" , Linux ARM , Linux Kernel Mailing List , linux-samsung-soc , linux-clk , "open list:GPIO SUBSYSTEM" , linux-rtc@vger.kernel.org, Arnd Bergmann X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211001_045959_047313_E89744A3 X-CRM114-Status: GOOD ( 22.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Olof, On Fri, Oct 1, 2021 at 7:36 AM Olof Johansson wrote: > A much more valuable approach would be to work towards being able to > free up memory by un-probed drivers at the end of boot. That would > possibly benefit all platforms on all architectures. We used to have such a functionality in arch/ppc (not arch/powerpc!), where code/data could be tagged __prep, __chrp, or __pmac, to put it in a special section, and to be freed with initdata when unused. It was removed in v2.6.15[1], as the savings weren't worth the hassle. In a more fragmented space like arm the memory lost due to alignment of the sections would be even more substantial. Another problem is to know when is the end of the boot, especially with deferred probing. [1] 6c45ab992e4299c8 ("[PATCH] powerpc: Remove section free() and linker script bits") Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel