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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6A5CC43441 for ; Thu, 29 Nov 2018 03:08:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 908F3206B2 for ; Thu, 29 Nov 2018 03:08:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OpkvW+IN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 908F3206B2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727349AbeK2OMf (ORCPT ); Thu, 29 Nov 2018 09:12:35 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:45967 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726954AbeK2OMe (ORCPT ); Thu, 29 Nov 2018 09:12:34 -0500 Received: by mail-pf1-f195.google.com with SMTP id g62so266161pfd.12 for ; Wed, 28 Nov 2018 19:08:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=2lMygJcHrzCNl4q8CsoRPaEEAZ7y2UvLdyTEjBhaeM4=; b=OpkvW+INGup/BeS7BqEn1jvP+ScT4H1LWIeXXCCY7CaX5DqKyhgE1KbRAcB1MjjrSB moW2rtvWDoON+cF62x1lSM/SscJ05w7Cxam1IgCCB/3wfR4p0BzEws/3KJ/By/3nZ4Zl aD4jmxIz93Rke/i4/4raPxo9z4DeD88knQtKrqCQCoxarmLlLvlbWahLokx1POLyPeWD yOJOqeUXnamQLNfROfDS5LGSbpSQXcQXURwLMDi0ZFmSxhUjYg2VzcB/VZDLrO3g1Hi9 uXBecye3+s7GRQ3LA5lgmdQLVu0lp8/wsXijDLz2yE+Kk9RkrYzs+gLHON8EV5iQxlO0 uxkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=2lMygJcHrzCNl4q8CsoRPaEEAZ7y2UvLdyTEjBhaeM4=; b=VvkQpFC/UA+qgfJXT7dM4sg29rVT+Q2AaP1eyWL81iKmt9LjcDOkfgpdvacw7u0XG4 iVdzSzLmppVzNp5FZwTzEM9X+es5pbOj9n14HUWO3KeZeKezKItPHTsA7XDyfbgMVnYS /1lLxqJkU84Br00MHjP7nKRrIdMq1Fojw2c9WbnA7+TwKBkfboZEqGqhThqemVJ2DsJL b5OrkYEHONbNgp+WtXFAsAr6MPBYsyjj3sXgELyVvm/24Ev7R8wOysIBmhnS622w7qmZ YVeFSZ6HEWP3JVk8flBcUdm0Tc9nZOUODlHRihxOBDggy1CfifLQgplVeFy2nDmvnV5v MXSA== X-Gm-Message-State: AA+aEWa74Ee5OtrtQAgMrHwJM7nEDavlHp7KUoh5i2qCBt7fctFXP0TO Ly+xKGwCxyBx4pM1tNZU8No= X-Google-Smtp-Source: AFSGD/VqVxZNgPMspDJ7YbFASFyLFh8rQolq7ER6IuHQmM1foPdtG4kXdxxDABL42ohKQ9Hcur63qw== X-Received: by 2002:a62:9fd9:: with SMTP id v86mr17910817pfk.191.1543460924404; Wed, 28 Nov 2018 19:08:44 -0800 (PST) Received: from localhost ([175.223.15.27]) by smtp.gmail.com with ESMTPSA id e9sm489999pff.5.2018.11.28.19.08.42 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 28 Nov 2018 19:08:43 -0800 (PST) Date: Thu, 29 Nov 2018 12:08:40 +0900 From: Sergey Senozhatsky To: Dave Rodgman Cc: "linux-kernel@vger.kernel.org" , nd , "herbert@gondor.apana.org.au" , "davem@davemloft.net" , Matt Sealey , "nitingupta910@gmail.com" , "rpurdie@openedhand.com" , "markus@oberhumer.com" , "minchan@kernel.org" , "sergey.senozhatsky.work@gmail.com" , "sonnyrao@google.com" , "gregkh@linuxfoundation.org" , "akpm@linux-foundation.org" Subject: Re: [PATCH 6/7] lib/lzo: implement run-length encoding Message-ID: <20181129030840.GF6379@jagdpanzerIV> References: <20181127161913.23863-1-dave.rodgman@arm.com> <20181127161913.23863-7-dave.rodgman@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181127161913.23863-7-dave.rodgman@arm.com> User-Agent: Mutt/1.11.0 (2018-11-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (11/27/18 16:19), Dave Rodgman wrote: > > This modifies the bitstream in a way which is backwards compatible > (i.e., we can decompress old bitstreams, but old versions of lzo > cannot decompress new bitstreams). > Hmmm... Whoa. Help me understand this: So a btrfs filesystem, compressed with the new lzo, say I run 4.21, won't be readable at all once I reboot under 4.19? What about compressed net traffic between servers running different kernel version (one with new lzo, the other one with old lzo)? XFRM can be compressed with lzo, can't it? -ss