From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org ([103.22.144.67]:43635 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751575AbaHTTrE (ORCPT ); Wed, 20 Aug 2014 15:47:04 -0400 From: Rusty Russell Subject: Re: [PATCH 2/3] kbuild: handle module compression while running 'make modules_install'. In-Reply-To: <1408474660-24999-3-git-send-email-beber@meleeweb.net> References: <1408474660-24999-1-git-send-email-beber@meleeweb.net> <1408474660-24999-3-git-send-email-beber@meleeweb.net> Date: Thu, 21 Aug 2014 01:39:59 +0930 Message-ID: <87r40bi1m0.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Bertrand Jacquin , linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Willy Tarreau Bertrand Jacquin writes: > Since module-init-tools (gzip) and kmod (gzip and xz) support compressed > modules, it could be useful to include a support for compressing modules > right after having them installed. Doing this in kbuild instead of per > distro can permit to make this kind of usage more generic. > > This patch add a Kconfig entry to "Enable loadable module support" menu > and let you choose to compress using gzip (default) or xz. > > Both gzip and xz does not used any extra -[1-9] option since Andi Kleen > and Rusty Russell prove no gain is made using them. gzip is called with -n > argument to avoid storing original filename inside compressed file, that > way we can save some more bytes. > > On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a > total of 378MB (no strip, no sign, no compress), the following table > shows observed disk space gain based on the allmodconfig .config : > > | time | > +-------------+-----------------+ > | manual .ko | make | size | percent > | compression | modules_install | | gain > +-------------+-----------------+------+-------- > - | | 18.61s | 378M | > GZIP | 3m16s | 3m37s | 102M | 73.41% > XZ | 5m22s | 5m39s | 77M | 79.83% > > The gain for restricted environnement seems to be interesting while > uncompress can be time consuming but happens only while loading a module, > that is generally done only once. > > 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. > > Reviewed-by: Willy Tarreau > Signed-off-by: Bertrand Jacquin Thanks, applied these two as well. They'll go in *next* merge window (ie. 3.18). Cheers. Rusty.