From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935413AbcJUVWC (ORCPT ); Fri, 21 Oct 2016 17:22:02 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35275 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935054AbcJUVWA (ORCPT ); Fri, 21 Oct 2016 17:22:00 -0400 Date: Fri, 21 Oct 2016 14:21:54 -0700 From: Andrew Morton To: klondike Cc: linux-kernel@vger.kernel.org, P J P , Paul Bolle Subject: Re: [PATCH v3 2/2] initramfs: Allow again choice of the embedded initram compression algorithm Message-Id: <20161021142154.211eb0ae3784e055429a92e3@linux-foundation.org> In-Reply-To: <57EAD77B.7090607@klondike.es> References: <54239E69.4050803@klondike.es> <57EAC8CC.3070602@klondike.es> <57EAD3BC.9050802@klondike.es> <57EAD77B.7090607@klondike.es> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Sep 2016 22:32:59 +0200 klondike wrote: > Choosing the appropriate compression option when using an embeded initramfs > can result in significant size differences in the resulting data. > > This is caused by avoiding double compression of the initramfs contents. > For example on my tests, choosing CONFIG_INITRAMFS_COMPRESSION_NONE when > compressing the kernel using XZ) results in up to 500KiB differences (9MiB to > 8.5MiB) in the kernel size as the dictionary will not get polluted with > uncomprensible data and may reuse kernel data too. > > Despite embedding an uncompressed initramfs, a user may want to allow for a > compressed extra initramfs to be passed using the rd system, for example to > boot a recovery system. Commit 9ba4bcb645898d562498ea66a0df958ef0e7a68c > ("initramfs: read CONFIG_RD_ variables for initramfs compression") broke > that behavior by making the choice based on CONFIG_RD_* instead of adding > CONFIG_INITRAMFS_COMPRESSION_LZ4. Saddly, CONFIG_RD_* is also used to > choose the supported RD compression algorithms by the kernel and a user may > want to suppport more than one. > > This patch also reverses 3e4e0f0a8756dade3023d1f47d50fbced7749788 > ("initramfs: remove "compression mode" choice") restoring back the > "compression mode" choice and includes the CONFIG_INITRAMFS_COMPRESSION_LZ4 > option which was never added. > > As a result the following options are added or readed affecting the embedded > initramfs compression: > INITRAMFS_COMPRESSION_NONE Do no compression > INITRAMFS_COMPRESSION_GZIP Compress using gzip > INITRAMFS_COMPRESSION_BZIP2 Compress using bzip2 > INITRAMFS_COMPRESSION_LZMA Compress using lzma > INITRAMFS_COMPRESSION_XZ Compress using xz > INITRAMFS_COMPRESSION_LZO Compress using lzo > INITRAMFS_COMPRESSION_LZ4 Compress using lz4 > > These depend on the corresponding CONFIG_RD_* option being set (except NONE > which has no dependencies). As you sent them, these patches would be merged with From: klondike Signed-off-by: Francisco Blas Izquierdo Riera (klondike) Which is strange. Different email addresses and "klondike" isn't a real name. So I'll rewrite the From: address to match the SOB address. You can do this yourself by including an explicit From: line as the first line of the changelog text.