Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261502AbVDZNF5 (ORCPT ); Tue, 26 Apr 2005 09:05:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261503AbVDZNF5 (ORCPT ); Tue, 26 Apr 2005 09:05:57 -0400 Received: from colin.muc.de ([193.149.48.1]:19216 "EHLO colin2.muc.de") by vger.kernel.org with ESMTP id S261502AbVDZNFt (ORCPT ); Tue, 26 Apr 2005 09:05:49 -0400 Date: 26 Apr 2005 15:05:48 +0200 Date: Tue, 26 Apr 2005 15:05:47 +0200 From: Andi Kleen To: Takashi Ikebe Cc: Valdis.Kletnieks@vt.edu, Kyle Moffett , linux-kernel@vger.kernel.org Subject: Re: [PATCH x86_64] Live Patching Function on 2.6.11.7 Message-ID: <20050426130547.GE65287@muc.de> References: <4263275A.2020405@lab.ntt.co.jp> <426C51C4.9040902@lab.ntt.co.jp> <426CC8F7.8070905@lab.ntt.co.jp> <200504251636.j3PGa9SJ015388@turing-police.cc.vt.edu> <426D9AC0.5020908@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <426D9AC0.5020908@lab.ntt.co.jp> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1648 Lines: 38 On Tue, Apr 26, 2005 at 10:34:56AM +0900, Takashi Ikebe wrote: > I think that's the common sense in every carrier. > If we reboot the switch, the service will be disrupted. > The phone network is lifeline, and does not allow to be disrupt by just > bug fix. > I think same kind of function is needed in many real > enterprise/mission-critical/business area. > > All do with ptrace may affect target process's time critical task. (need > to stop target process whenever fix) Sorry, but what are your exact time requirements for this? Remember any x86-64 CPU is really fast and it can do a _lot_ of ptrace operations in a very short time. Just a vague "it may be too slow" is not enough justification to push a lot of redundant code into the kernel. Also if ptrace should be really too slow (which I doubt, but you are welcome to show some numbers together with real time requirements from a real system) then we could optimize ptrace for this, e.g. by adding a ptrace subcommand to copy whole memory blocks more efficiently or maybe even do a mmap like thing. But unless someone actually demonstrates this is needed it seems far overkill. > All implement in user application costs too much, need to implement all > the application...(and I do not know this approach really works on time > critical applications yet.) I think you have a lot of unproved and doubtful assumptions here. -Andi - 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/