linux-kernel - Re: [RFC PATCH 6/9] livepatch: create per-task consistency model

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20150212123906.GC23367@worktop.ger.corp.intel.com>
Date:	Thu, 12 Feb 2015 13:39:06 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Jiri Kosina <jkosina@...e.cz>
Cc:	Josh Poimboeuf <jpoimboe@...hat.com>,
	Ingo Molnar <mingo@...hat.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	live-patching@...r.kernel.org, linux-kernel@...r.kernel.org,
	Seth Jennings <sjenning@...hat.com>,
	Vojtech Pavlik <vojtech@...e.cz>
Subject: Re: [RFC PATCH 6/9] livepatch: create per-task consistency model

On Thu, Feb 12, 2015 at 01:25:14PM +0100, Jiri Kosina wrote:
> On Thu, 12 Feb 2015, Peter Zijlstra wrote:
> 
> > Its not at all clear how all this would work to me. And I'm not
> > motivated enough to go try and reverse engineer your patch; IMO
> > livepatching is utter fail.
> > 
> > If your infrastructure relies on the uptime of a single machine you've
> > lost already.
> 
> Well, the fact indisputable fact is that there is a demand for this. It's 
> not about one machine, it's about scheduling dowtimes of datacentres.

The changelog says:

 > ... A patch can remain in the
 > transition state indefinitely, if any of the tasks are stuck in the
 > previous universe.

Therefore there is no scheduling anything. Without timeliness guarantees
you can't make a schedule.

Might as well just reboot, at least that's fairly well guaranteed to
happen.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/