Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932185AbbFDU0U (ORCPT ); Thu, 4 Jun 2015 16:26:20 -0400 Received: from ozlabs.org ([103.22.144.67]:33137 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752773AbbFDU0R (ORCPT ); Thu, 4 Jun 2015 16:26:17 -0400 From: Rusty Russell To: Lucas De Marchi Cc: Andreas Mohr , Andrew Morton , Bertrand Jacquin , "Marco d'Itri" , linux-modules , lkml , Jon Masters Subject: Re: [PATCH] modules: CONFIG_MODULE_COMPRESS: add hint that userspace support may easily be missing. In-Reply-To: References: <20150531152932.GA16337@rhlx01.hs-esslingen.de> <87r3pwgd0b.fsf@rustcorp.com.au> <87h9qouuny.fsf@rustcorp.com.au> User-Agent: Notmuch/0.17 (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Fri, 05 Jun 2015 05:52:24 +0930 Message-ID: <87zj4fte9r.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3159 Lines: 77 Lucas De Marchi writes: >> + gzip and xz (but doesn't by default, at least as of version 18!). > > This is pretty much misleading. There's no such a default option. It's > like saying kernel doesn't support feature X, Y or Z by default > because make defconfig doesn't turn them on. Nobody except Linus expects a defconfig to boot. I expect ./configure to give me a working tool; these *are* defaults, and setting them *is* your responsibility as author. When it became an in-kernel option rather than some weird distro thing, the old default was wrong. ... Though I hadn't realized that Marco had deliberately decided to leave support off. Surprising, since liblzma and libz seem required on Debian anyway. So I'm sorry Andreas: if your maintainer doesn't care about your case, there's not much I can do :( Subject: modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr Signed-off-by: Rusty Russell diff --git a/init/Kconfig b/init/Kconfig index 968a001790af..bcb7e1e13f7d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1948,26 +1948,21 @@ config MODULE_COMPRESS bool "Compress modules on installation" depends on MODULES help - This option compresses the kernel modules when 'make - modules_install' is run. - The modules will be compressed either using gzip or xz depend on the - choice made in "Compression algorithm". + Compresses kernel modules when 'make modules_install' is run; gzip or + xz depending on "Compression algorithm" below. - module-init-tools has support for gzip format while kmod handle gzip - and xz compressed modules. + module-init-tools MAY support gzip, and kmod MAY support gzip and xz. - When a kernel module is installed from outside of the main kernel - source and uses the Kbuild system for installing modules then that - kernel module will also be compressed when it is installed. + Out-of-tree kernel modules installed using Kbuild will also be + compressed upon installation. - This option provides little benefit when the modules are to be used inside - an initrd or initramfs, it generally is more efficient to compress the whole - initrd or initramfs instead. + Note: for modules inside an initrd or initramfs, it's more efficient + to compress the whole initrd or initramfs instead. - This is fully compatible with signed modules while the signed module is - compressed. module-init-tools or kmod handles decompression and provide to - other layer the uncompressed but signed payload. + Note: This is fully compatible with signed modules. + + If in doubt, say N. choice prompt "Compression algorithm" -- 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/