From: Robert Hancock <hancockr@shaw.ca>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <ak@suse.de>,
linux-kernel@vger.kernel.org, Neil Brown <neilb@suse.de>,
"Rafael J. Wysocki" <rjw@sisk.pl>, Ingo Molnar <mingo@elte.hu>,
Zwane Mwaikambo <zwane@linuxpower.ca>
Subject: Re: [PATCH] x86: Document the hotplug code is incompatible with x86 irq handling
Date: Thu, 31 May 2007 08:34:28 -0600 [thread overview]
Message-ID: <465EDCF4.7010700@shaw.ca> (raw)
In-Reply-To: <fa.tUMR7tAB+jMgtfyl/LJ7U9QMgBs@ifi.uio.no>
Eric W. Biederman wrote:
> I just realized that except for doing the code review and noticing
> that the current cpu hotplug code is fundamentally incompatible
> with x86 I haven't done anything about it. So here is my patch
> to document what is wrong.
>
> The current cpu hotplug code requires irqs to be migrated from a cpu
> outside of irq context. On x86 ioapics simply do not support this,
> making the code unfixable without major redesign of the generic cpu
> hotplug code.
>
> So this patch makes CPU_HOTPLUG on x86 depend on CONFIG_BROKEN
> and adds a WARN_ON so people that do enable it are not in doubt about
> which part of the code is broken, even if it does work for them.
>
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
I don't think this is useful, though the code may be problematic, this
patch will break suspend on all SMP machines with an existing config,
which is a major regression..
--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/
next parent reply other threads:[~2007-05-31 14:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <fa.tUMR7tAB+jMgtfyl/LJ7U9QMgBs@ifi.uio.no>
2007-05-31 14:34 ` Robert Hancock [this message]
2007-05-31 15:47 ` [PATCH] x86: Document the hotplug code is incompatible with x86 irq handling Eric W. Biederman
2007-05-31 20:12 ` Rafael J. Wysocki
2007-06-01 19:48 ` Eric W. Biederman
2007-06-01 20:06 ` Rafael J. Wysocki
2007-06-01 20:29 ` Eric W. Biederman
2007-06-01 20:44 ` Rafael J. Wysocki
2007-06-01 20:34 ` Rafael J. Wysocki
2007-05-31 13:32 Eric W. Biederman
2007-06-07 14:01 ` Pavel Machek
2007-06-12 18:19 ` Eric W. Biederman
2007-06-12 20:52 ` Rafael J. Wysocki
2007-06-12 21:56 ` Siddha, Suresh B
2007-06-12 22:16 ` Rafael J. Wysocki
2007-06-12 22:24 ` Siddha, Suresh B
2007-06-12 22:58 ` Rafael J. Wysocki
2007-06-22 17:27 ` Eric W. Biederman
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