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From: Peter Zijlstra <peterz@infradead.org>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
	Ingo Molnar <mingo@redhat.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
	Seth Jennings <sjenning@redhat.com>,
	Vojtech Pavlik <vojtech@suse.cz>
Subject: Re: [RFC PATCH 6/9] livepatch: create per-task consistency model
Date: Thu, 12 Feb 2015 13:39:06 +0100	[thread overview]
Message-ID: <20150212123906.GC23367@worktop.ger.corp.intel.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1502121319440.20672@pobox.suse.cz>

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.

  parent reply	other threads:[~2015-02-12 12:39 UTC|newest]

Thread overview: 106+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-09 17:31 [RFC PATCH 0/9] livepatch: consistency model Josh Poimboeuf
2015-02-09 17:31 ` [RFC PATCH 1/9] livepatch: simplify disable error path Josh Poimboeuf
2015-02-13 12:25   ` Miroslav Benes
2015-02-18 17:03     ` Petr Mladek
2015-02-18 20:07   ` Jiri Kosina
2015-02-09 17:31 ` [RFC PATCH 2/9] livepatch: separate enabled and patched states Josh Poimboeuf
2015-02-10 16:44   ` Jiri Slaby
2015-02-10 17:21     ` Josh Poimboeuf
2015-02-13 12:57   ` Miroslav Benes
2015-02-13 14:39     ` Josh Poimboeuf
2015-02-13 14:46       ` Miroslav Benes
2015-02-09 17:31 ` [RFC PATCH 3/9] livepatch: move patching functions into patch.c Josh Poimboeuf
2015-02-10 18:27   ` Jiri Slaby
2015-02-10 18:50     ` Josh Poimboeuf
2015-02-13 14:28   ` Miroslav Benes
2015-02-13 15:09     ` Josh Poimboeuf
2015-02-09 17:31 ` [RFC PATCH 4/9] livepatch: get function sizes Josh Poimboeuf
2015-02-10 18:30   ` Jiri Slaby
2015-02-10 18:53     ` Josh Poimboeuf
2015-02-09 17:31 ` [RFC PATCH 5/9] sched: move task rq locking functions to sched.h Josh Poimboeuf
2015-02-10 10:48   ` Masami Hiramatsu
2015-02-10 14:54     ` Josh Poimboeuf
2015-02-09 17:31 ` [RFC PATCH 6/9] livepatch: create per-task consistency model Josh Poimboeuf
2015-02-10 10:58   ` Masami Hiramatsu
2015-02-10 14:59     ` Josh Poimboeuf
2015-02-10 15:59   ` Miroslav Benes
2015-02-10 16:56     ` Josh Poimboeuf
2015-02-11 16:28       ` Miroslav Benes
2015-02-11 20:23         ` Josh Poimboeuf
2015-02-10 19:27   ` Seth Jennings
2015-02-10 19:32     ` Josh Poimboeuf
2015-02-11 10:21   ` Miroslav Benes
2015-02-11 20:19     ` Josh Poimboeuf
2015-02-12 10:45       ` Miroslav Benes
2015-02-12  3:21   ` Josh Poimboeuf
2015-02-12 11:56     ` Peter Zijlstra
2015-02-12 12:25       ` Jiri Kosina
2015-02-12 12:36         ` Peter Zijlstra
2015-02-12 12:39           ` Jiri Kosina
2015-02-12 12:39         ` Peter Zijlstra [this message]
2015-02-12 12:42           ` Jiri Kosina
2015-02-12 13:01             ` Josh Poimboeuf
2015-02-12 12:51       ` Josh Poimboeuf
2015-02-12 13:08         ` Peter Zijlstra
2015-02-12 13:16           ` Jiri Kosina
2015-02-12 14:20             ` Josh Poimboeuf
2015-02-12 14:27               ` Jiri Kosina
2015-02-12 13:16           ` Jiri Slaby
2015-02-12 13:35             ` Peter Zijlstra
2015-02-12 14:08               ` Jiri Kosina
2015-02-12 15:24                 ` Josh Poimboeuf
2015-02-12 14:20               ` Jiri Slaby
2015-02-12 14:32           ` Jiri Kosina
2015-02-18 20:17             ` Ingo Molnar
2015-02-18 20:44               ` Vojtech Pavlik
2015-02-19  9:52                 ` Peter Zijlstra
2015-02-19 10:11                   ` Vojtech Pavlik
2015-02-19 10:51                     ` Peter Zijlstra
2015-02-12 13:26     ` Jiri Slaby
2015-02-12 15:48       ` Josh Poimboeuf
2015-02-14 11:40   ` Jiri Slaby
2015-02-17 14:59     ` Josh Poimboeuf
2015-02-16 14:19   ` Miroslav Benes
2015-02-17 15:10     ` Josh Poimboeuf
2015-02-17 15:48       ` Miroslav Benes
2015-02-17 16:01         ` Josh Poimboeuf
2015-02-18 12:42           ` Miroslav Benes
2015-02-18 13:15             ` Josh Poimboeuf
2015-02-18 13:42               ` Miroslav Benes
2015-02-09 17:31 ` [RFC PATCH 7/9] proc: add /proc/<pid>/universe to show livepatch status Josh Poimboeuf
2015-02-10 18:47   ` Jiri Slaby
2015-02-10 18:57     ` Josh Poimboeuf
2015-02-09 17:31 ` [RFC PATCH 8/9] livepatch: allow patch modules to be removed Josh Poimboeuf
2015-02-10 19:02   ` Jiri Slaby
2015-02-10 19:57     ` Josh Poimboeuf
2015-02-11 10:55       ` Jiri Slaby
2015-02-11 18:39         ` Josh Poimboeuf
2015-02-12 15:22     ` Miroslav Benes
2015-02-13 12:44       ` Josh Poimboeuf
2015-02-13 16:04       ` Josh Poimboeuf
2015-02-13 16:17         ` Miroslav Benes
2015-02-13 20:49           ` Josh Poimboeuf
2015-02-16 16:06             ` Miroslav Benes
2015-02-17 15:55               ` Josh Poimboeuf
2015-02-17 16:38                 ` Miroslav Benes
2015-02-09 17:31 ` [RFC PATCH 9/9] livepatch: update task universe when exiting kernel Josh Poimboeuf
2015-02-16 10:16   ` Jiri Slaby
2015-02-17 14:58     ` Josh Poimboeuf
2015-02-09 23:15 ` [RFC PATCH 0/9] livepatch: consistency model Jiri Kosina
2015-02-10  3:05   ` Josh Poimboeuf
2015-02-10  7:21     ` Jiri Kosina
2015-02-10  8:57 ` Jiri Kosina
2015-02-10 14:43   ` Josh Poimboeuf
2015-02-10 11:16 ` Masami Hiramatsu
2015-02-10 15:59   ` Josh Poimboeuf
2015-02-10 17:29     ` Josh Poimboeuf
2015-02-13 10:14 ` Jiri Kosina
2015-02-13 14:19   ` Josh Poimboeuf
2015-02-13 14:22     ` Jiri Kosina
2015-02-13 14:40       ` Miroslav Benes
2015-02-13 14:55         ` Josh Poimboeuf
2015-02-13 14:41       ` Josh Poimboeuf
2015-02-24 11:27         ` Masami Hiramatsu
2015-03-10 16:23 ` Josh Poimboeuf
2015-03-10 21:02   ` Jiri Kosina
2015-03-10 21:30     ` Josh Poimboeuf

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