Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755265AbZCZHxm (ORCPT ); Thu, 26 Mar 2009 03:53:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754754AbZCZHwx (ORCPT ); Thu, 26 Mar 2009 03:52:53 -0400 Received: from mu-out-0910.google.com ([209.85.134.186]:19731 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754706AbZCZHwv (ORCPT ); Thu, 26 Mar 2009 03:52:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=myW9HUC9Z7QuJbv0bKzkmdq9Ag5J9UQE0vg0Sb1vuGrIyzR7XYdA3ROqoB6k1sA97A khlKU57IwmtwqBhe4Q0wbSk6qG05HKerqRAoablnto3x1H60BBA26eunU3VqDDq1yWdZ fICDUEEXnu9uvJBejXASyEwCi85+gXXjWYAF4= Subject: Re: fastboot: unpacking initramfs faster From: Andreas Robinson To: 7eggert@gmx.de Cc: Arjan van de Ven , linux-kernel@vger.kernel.org In-Reply-To: References: Content-Type: text/plain Date: Thu, 26 Mar 2009 08:52:44 +0100 Message-Id: <1238053964.8304.24.camel@andreas-desktop> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1482 Lines: 34 On Tue, 2009-03-24 at 23:11 +0100, Bodo Eggert wrote: > Andreas Robinson wrote: > > > I tried running the initramfs unpacking asynchronously (and earlier) but > > ran into a curious problem: The parent thread stalled until > > decompression was done. I don't know why - I made sure that the two > > threads ran on different cores. Perhaps the parent was cache starved. > > I could not stall my system by gzip/dev/null. > Maybe you accidentally used vfork? No, this was an in-kernel test. I used the Arjan's new async facility which calls kthread_create(). > > I then looked at multithreaded decompression and found that neither gzip > > files nor deflate streams provide enough information (eg block lengths) > > to let you share the decompression among threads. > > > > It can be done of course, but obviously not without modifying file > > formats and userspace tools. > > > > (Thoughts of snowballs and hell presented themselves at this point.) > > Why not make a new set? http://7eggert.dyndns.org:8080/l/bgz.tar.gz Hmm, well if you think there is a chance of it being accepted, then sure! I'll cook something up, but will be looking to use LZO first since it's a bit faster to begin with. -- 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/