All of lore.kernel.org
 help / color / mirror / Atom feed
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 18:11:49 +1100	[thread overview]
Message-ID: <400CD4B5.6020507@cyberone.com.au> (raw)
In-Reply-To: <20040120065207.GA10993@hockin.org>



Tim Hockin wrote:

>On Tue, Jan 20, 2004 at 05:43:59PM +1100, Nick Piggin wrote:
>
>>>I think the sanest thing for a CPU removal is to migrate everything off the
>>>processor in question, move unrunnable tasks into TASK_UNRUNNABLE state,
>>>then notify /sbin/hotplug.  The hotplug script can then find and handle the
>>>unrunnable tasks.  No SIGPWR grossness needed.
>>>
>>>Code against 2.4 at http://www.hockin.org/~thockin/procstate - it was
>>>heavily tested and I *think* it is all correct (for that kernel snapshot).
>>>
>>Seems less robust and more ad hoc than SIGPWR, however.
>>
>
>Disagree.  SIGPWR will kill any process that doesn't catch it.  That's
>policy.  It seems more robust to let the hotplug script decide what to do.
>If it wants to kill each unrunnable task with SIGPWR, it can.  But if it
>wants to let them live, it can.
>

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 dropped lhcs-devel@lists.sourceforge.net because its moderated)



  reply	other threads:[~2004-01-20  7:23 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 [this message]
2004-01-20  7:30           ` Tim Hockin
2004-01-20  7:45             ` Nick Piggin
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=400CD4B5.6020507@cyberone.com.au \
    --to=piggin@cyberone.com.au \
    --cc=akpm@osdl.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rml@tech9.net \
    --cc=rusty@au1.ibm.com \
    --cc=thockin@hockin.org \
    --cc=torvalds@osdl.org \
    --cc=vatsa@in.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.