From: Nick Piggin <piggin@cyberone.com.au>
To: Tim Hockin <thockin@hockin.org>
Cc: Rusty Russell <rusty@au1.ibm.com>,
vatsa@in.ibm.com, linux-kernel@vger.kernel.org,
torvalds@osdl.org, akpm@osdl.org, rml@tech9.net
Subject: Re: CPU Hotplug: Hotplug Script And SIGPWR
Date: Tue, 20 Jan 2004 18:45:37 +1100 [thread overview]
Message-ID: <400CDCA1.5070200@cyberone.com.au> (raw)
In-Reply-To: <20040120073032.GB12638@hockin.org>
Tim Hockin wrote:
>On Tue, Jan 20, 2004 at 06:11:49PM +1100, Nick Piggin wrote:
>
>>I thought hotplug is allowed to fail? Thus you can have a hung system.
>>Or what if the hotplug script itself becomes TASK_UNRUNNABLE? What if the
>>process needs a guaranteed scheduling latency?
>>
>
>I guess a hotplug script MAY fail. I don't think it's a good idea to make
>your CPU hotplug script fail. May and Misght are different. It's up to the
>implementor whether the script can get into a failure condition.
>
Sorry bad wording. The script may fail to be executed.
>
>The hotplug script can only become unrunnable if you yank out all the CPUs
>on the system. I'd assume it would have an affinity of 0xffffffff.
>
OK I guess thats not such a valid concern
>
>What if <which> process needs guaranteed scheduling latency? Do we really
>_guarantee_ scheduling latency *anywhere*?
>
>
We do guarantee that a realtime task won't be blocked waiting for
a hotplug script to fault in and start it up again (which may not
happen). Not sure how important this issue is.
next prev parent reply other threads:[~2004-01-20 7:45 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20040116174446.A2820@in.ibm.com>
2004-01-20 5:44 ` CPU Hotplug: Hotplug Script And SIGPWR Rusty Russell
2004-01-20 6:33 ` Tim Hockin
2004-01-20 6:43 ` Nick Piggin
2004-01-20 6:52 ` Tim Hockin
2004-01-20 7:11 ` Nick Piggin
2004-01-20 7:30 ` Tim Hockin
2004-01-20 7:45 ` Nick Piggin [this message]
2004-01-20 7:54 ` Tim Hockin
2004-01-20 8:14 ` Nick Piggin
2004-01-20 8:29 ` Tim Hockin
2004-01-20 8:37 ` Nick Piggin
2004-01-20 8:43 ` Tim Hockin
2004-01-21 4:06 ` Srivatsa Vaddagiri
2004-01-21 4:14 ` Nick Piggin
2004-01-21 5:09 ` Srivatsa Vaddagiri
2004-01-21 7:08 ` Tim Hockin
2004-01-21 15:07 ` Matthias Urlichs
2004-01-22 5:29 ` Rusty Russell
2004-01-21 7:09 ` Tim Hockin
2004-01-21 7:31 ` Nick Piggin
2004-01-21 7:42 ` Tim Hockin
2004-01-21 8:11 ` Rusty Russell
2004-01-21 5:07 ` Rusty Russell
2004-01-20 8:41 ` Stefan Smietanowski
2004-01-20 8:49 ` Nick Piggin
2004-01-20 9:12 ` Tim Hockin
2004-01-21 0:00 ` Rusty Russell
2004-01-20 23:51 ` Rusty Russell
2004-01-20 7:45 ` Rusty Russell
2004-01-20 8:37 ` Tim Hockin
2004-01-20 9:29 ` Srivatsa Vaddagiri
2004-01-21 0:12 ` Rusty Russell
[not found] <fa.f37o48p.1io5q5@ifi.uio.no>
[not found] ` <fa.frjqvfo.170g8hq@ifi.uio.no>
2004-01-20 17:49 ` Andy Lutomirski
2004-01-21 4:33 ` Rusty Russell
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