linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Rusty Russell <rusty@rustcorp.com.au>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>,
	rusty@au1.ibm.com, Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@osdl.org>,
	lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
	LHCS list <lhcs-devel@lists.sourceforge.net>
Subject: Re: [Experimental CPU Hotplug PATCH] - Move migrate_all_tasks to CPU_DEAD handling
Date: Wed, 07 Apr 2004 13:54:34 +1000	[thread overview]
Message-ID: <1081310073.5922.86.camel@bach> (raw)
In-Reply-To: <407277AE.2050403@yahoo.com.au>

On Tue, 2004-04-06 at 19:26, Nick Piggin wrote:
> Note there was already that check in the wakeup path, although
> I suspect it was someone being overly cautious and isn't required.

No, it really is required.

The stop_machine thread runs on the cpu, then kicks everyone else off,
then does a complete() (in stop_machine.c:do_stop()).  Without this
check, the complete() drags the sleeping process (which called
stop_machine) onto the dying CPU.

Hmm, maybe we could explicitly exclude downed cpu from calling task's
mask.  Kind of hacky: theoretically you should never modify a task's
affinity unless the user actually asked for it (since anyone can ask for
another tasks affinity).

Cheers!
Rusty.
-- 
Anyone who quotes me in their signature is an idiot -- Rusty Russell


  parent reply	other threads:[~2004-04-07  3:55 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-04-05 12:18 [Experimental CPU Hotplug PATCH] - Move migrate_all_tasks to CPU_DEAD handling Srivatsa Vaddagiri
2004-04-06  0:28 ` Nick Piggin
2004-04-06  1:15   ` Srivatsa Vaddagiri
2004-04-06  1:27     ` Nick Piggin
2004-04-06  1:30       ` Nick Piggin
2004-04-06 16:43     ` [lhcs-devel] " Srivatsa Vaddagiri
2004-04-06  8:37   ` Srivatsa Vaddagiri
2004-04-06  9:26     ` Nick Piggin
2004-04-06 14:56       ` Srivatsa Vaddagiri
2004-04-06 15:04         ` Nick Piggin
2004-04-06 15:20           ` Srivatsa Vaddagiri
2004-04-07  3:54       ` Rusty Russell [this message]
2004-04-07  4:11         ` Nick Piggin
2004-04-07  5:01         ` Srivatsa Vaddagiri
2004-04-07  5:32           ` Rusty Russell
2004-04-07 14:17             ` Srivatsa Vaddagiri
2004-04-07 22:55               ` Rusty Russell
2004-04-12 16:08               ` [lhcs-devel] " Srivatsa Vaddagiri
2004-04-06  7:25 ` Ingo Molnar
2004-04-06 14:53   ` Srivatsa Vaddagiri
2004-04-06 15:03   ` Srivatsa Vaddagiri

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=1081310073.5922.86.camel@bach \
    --to=rusty@rustcorp.com.au \
    --cc=akpm@osdl.org \
    --cc=lhcs-devel@lists.sourceforge.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=nickpiggin@yahoo.com.au \
    --cc=rusty@au1.ibm.com \
    --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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).