mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
	tigran@aivazian.fsnet.co.uk, tglx@linutronix.de, mingo@elte.hu,
	hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org,
	Linux PM mailing list <linux-pm@lists.linux-foundation.org>
Subject: Re: [BUGFIX][PATCH] Freezer, CPU hotplug, x86 Microcode: Fix task freezing failures
Date: Sun, 2 Oct 2011 12:50:23 -0700	[thread overview]
Message-ID: <20111002195023.GC31799@mtj.dyndns.org> (raw)
In-Reply-To: <4E88B5E0.6080503@linux.vnet.ibm.com>

Hello,

On Mon, Oct 03, 2011 at 12:35:04AM +0530, Srivatsa S. Bhat wrote:
> So, this patch addresses this issue by ensuring that microcode is not freed
> from kernel memory, nor invalidated when a CPU goes offline. Thus once the
> kernel gets the microcode during boot-up, it will never have to depend on
> userspace ever again to get microcode, since it never releases the copy it
> already has. So every run of the microcode callback for CPU online event will
> now succeed irrespective of whether userspace is frozen or not. As a result,
> this fixes the task freezing failure encountered while running CPU hotplug
> stress test along with suspend/resume operations simultaneously.

I'm not familiar with how microcode is supposed to be managed but is
it impossible for the newly hotplugged CPU (an actual hot unplug /
plug) may not like the microcode loaded for the previous CPU?  Isn't
that why CPU_DEAD was invalidating the microcode?

Thanks.

-- 
tejun

  parent reply	other threads:[~2011-10-02 19:50 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-02 19:05 Srivatsa S. Bhat
2011-10-02 19:36 ` Rafael J. Wysocki
2011-10-02 19:50 ` Tejun Heo [this message]
2011-10-02 20:04   ` Srivatsa S. Bhat
2011-10-03  0:40     ` Tejun Heo
2011-10-03  5:51       ` Srivatsa S. Bhat
2011-10-03  8:47         ` Borislav Petkov
2011-10-04  7:15           ` Tejun Heo
2011-10-04 13:15             ` Srivatsa S. Bhat
2011-10-04 13:46               ` Borislav Petkov
2011-10-04 17:14                 ` Borislav Petkov
2011-10-04 19:49                   ` Rafael J. Wysocki
2011-10-04 20:57                   ` Srivatsa S. Bhat
2011-10-05  7:21                     ` Borislav Petkov
2011-10-05  8:51                       ` Srivatsa S. Bhat
2011-10-05 20:26                         ` Rafael J. Wysocki
2011-10-05 21:15                           ` Srivatsa S. Bhat
2011-10-05 22:43                             ` Rafael J. Wysocki
2011-10-06  6:50                               ` Srivatsa S. Bhat
2011-10-06  8:34                                 ` Borislav Petkov
2011-10-06 15:47                                   ` Srivatsa S. Bhat
2011-10-06 18:11                                     ` Srivatsa S. Bhat
2011-10-06 20:35                                     ` [BUGFIX][PATCH RESEND] " Srivatsa S. Bhat
2011-10-06 22:13                                       ` Tejun Heo
2011-10-06 22:34                                         ` Borislav Petkov
2011-10-07 16:48                                           ` Srivatsa S. Bhat
2011-10-07 18:05                                             ` Borislav Petkov
2011-10-04 13:25             ` [BUGFIX][PATCH] " Borislav Petkov
2011-10-05  8:33         ` Srivatsa S. Bhat

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=20111002195023.GC31799@mtj.dyndns.org \
    --to=tj@kernel.org \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@lists.linux-foundation.org \
    --cc=mingo@elte.hu \
    --cc=rjw@sisk.pl \
    --cc=srivatsa.bhat@linux.vnet.ibm.com \
    --cc=tglx@linutronix.de \
    --cc=tigran@aivazian.fsnet.co.uk \
    --cc=x86@kernel.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

all inboxes | Powered by JetHome®