linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] ARM: Don't use complete() during __cpu_die
Date: Fri, 13 Feb 2015 17:30:00 +0000	[thread overview]
Message-ID: <20150213173000.GD8656@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20150213172141.GF2529@leverpostej>

On Fri, Feb 13, 2015 at 05:21:41PM +0000, Mark Rutland wrote:
> On Fri, Feb 13, 2015 at 04:27:25PM +0000, Russell King - ARM Linux wrote:
> > If it happens after __cpu_disable(), then that's a problem: the system
> > will have gone through all the expensive preparation by that time to
> > shut the CPU down, and it will expect the CPU to go offline.  The only
> > way it can come back at that point is by going through a CPU plug-in
> > cycle... which means going back through secondary_start_kernel.
> 
> This would happen within __cpu_disable, as the current
> platform_cpu_disable() call does, before it's too late to abort the
> hotplug.

Okay, in which case it all sounds fine, but what it does mean is that
we can't merge Stephen's patch since we have no real idea which cores
can be hotplugged.

I'd rather not add additional complexity when we know that it's not
going to work very well...

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.

  reply	other threads:[~2015-02-13 17:30 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-05 10:14 [PATCH v2] ARM: Don't use complete() during __cpu_die Krzysztof Kozlowski
2015-02-05 10:50 ` Russell King - ARM Linux
2015-02-05 11:00   ` Krzysztof Kozlowski
2015-02-05 11:08     ` Russell King - ARM Linux
2015-02-05 11:28   ` Mark Rutland
2015-02-05 11:30     ` Russell King - ARM Linux
2015-02-05 14:29   ` Paul E. McKenney
2015-02-05 16:11     ` Russell King - ARM Linux
2015-02-05 17:02       ` Paul E. McKenney
2015-02-05 17:34         ` Russell King - ARM Linux
2015-02-05 17:54           ` Paul E. McKenney
2015-02-10  1:24       ` Stephen Boyd
2015-02-10  1:37         ` Paul E. McKenney
2015-02-10  2:05           ` Stephen Boyd
2015-02-10  3:05             ` Paul E. McKenney
2015-02-10 15:14         ` Mark Rutland
2015-02-10 20:48           ` Stephen Boyd
2015-02-10 21:04             ` Stephen Boyd
2015-02-10 21:15               ` Russell King - ARM Linux
2015-02-10 21:49                 ` Stephen Boyd
2015-02-10 22:05                   ` Stephen Boyd
2015-02-13 15:52               ` Mark Rutland
2015-02-13 16:27                 ` Russell King - ARM Linux
2015-02-13 17:21                   ` Mark Rutland
2015-02-13 17:30                     ` Russell King - ARM Linux [this message]
2015-02-13 16:28                 ` Stephen Boyd
2015-02-13 15:38             ` Mark Rutland
2015-02-10 20:58           ` Russell King - ARM Linux
2015-02-10 15:41         ` Russell King - ARM Linux
2015-02-10 18:33           ` Stephen Boyd
2015-02-25 12:56       ` Russell King - ARM Linux
2015-02-25 16:47         ` Nicolas Pitre
2015-02-25 17:00           ` Russell King - ARM Linux
2015-02-25 18:13             ` Nicolas Pitre
2015-02-25 20:16               ` Nicolas Pitre
2015-02-26  1:05                 ` Paul E. McKenney
2015-03-22 23:30                   ` Paul E. McKenney
2015-03-23 12:55                     ` Russell King - ARM Linux
2015-03-23 13:21                       ` Paul E. McKenney
2015-03-23 14:00                         ` Russell King - ARM Linux
2015-03-23 15:37                           ` Paul E. McKenney
2015-03-23 16:56                             ` Paul E. McKenney
2015-02-26 19:14           ` Daniel Thompson
2015-02-26 19:47             ` Nicolas Pitre
2015-02-05 10:53 ` Mark Rutland
2015-02-05 10:59   ` Krzysztof Kozlowski

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=20150213173000.GD8656@n2100.arm.linux.org.uk \
    --to=linux@arm.linux.org.uk \
    --cc=linux-arm-kernel@lists.infradead.org \
    /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).