stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: ebiederm@xmission.com (Eric W. Biederman)
To: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>,
	linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Gleb Natapov <gleb@redhat.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Joerg Roedel <joro@8bytes.org>,
	x86@kernel.org, stable@vger.kernel.org,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>,
	Sebastian Andrzej Siewior <sebastian@breakpoint.cc>,
	Ingo Molnar <mingo@redhat.com>,
	Zhang Yanfei <zhangyanfei@cn.fujitsu.com>,
	yrl.pp-manager.tt@hitachi.com,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Seiji Aguchi <seiji.aguchi@hds.com>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] [BUGFIX] crash/ioapic: Prevent crash_kexec() from deadlocking of ioapic_lock
Date: Tue, 20 Aug 2013 03:12:32 -0700	[thread overview]
Message-ID: <871u5or7qn.fsf@tw-ebiederman.twitter.com> (raw)
In-Reply-To: <5212B31A.6090504@hitachi.com> (Yoshihiro YUNOMAE's message of "Tue, 20 Aug 2013 09:06:50 +0900")

Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> writes:

> Hi Ingo,
>
> Thank you for fixing typos!
> OK, I'll fix them and rename to ioapic_zap_locks().
>
> Thank you again!


The better fix for this would be to remove the disable_IO_APIC call from
crash_kexec.

I know last time it was investigated the kernel was very close to
working without needing that, and the code will be much more robust in
the long term if we can avoid disabling them in the crashing kernel.

Yoshihiro is there any chance you can look into removing the
disable_IO_APIC entirely?

The apic disablement and the disable_IO_APIC exists entirely due to
limitations in the kernel boot path.

Eric

  reply	other threads:[~2013-08-20 10:12 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-19  8:12 [PATCH] [BUGFIX] crash/ioapic: Prevent crash_kexec() from deadlocking of ioapic_lock Yoshihiro YUNOMAE
2013-08-19  9:46 ` Ingo Molnar
2013-08-20  0:06   ` Yoshihiro YUNOMAE
2013-08-20 10:12     ` Eric W. Biederman [this message]
2013-08-20 14:27       ` Don Zickus
2013-08-22  8:38         ` Yoshihiro YUNOMAE
2013-08-22 13:11           ` Don Zickus
2013-08-27  3:41             ` Yoshihiro YUNOMAE
2013-08-27 13:33               ` Don Zickus
2013-08-31  0:58                 ` Eric W. Biederman
2013-09-02  3:09                   ` Yoshihiro YUNOMAE
2013-09-03  0:12                     ` Eric W. Biederman
2013-09-03 11:02                       ` Yoshihiro YUNOMAE
2013-09-03 12:44                         ` Eric W. Biederman
2013-09-04  9:40                           ` Yoshihiro YUNOMAE

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=871u5or7qn.fsf@tw-ebiederman.twitter.com \
    --to=ebiederm@xmission.com \
    --cc=ak@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=gleb@redhat.com \
    --cc=hidehiro.kawai.ez@hitachi.com \
    --cc=hpa@zytor.com \
    --cc=joro@8bytes.org \
    --cc=konrad.wilk@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masami.hiramatsu.pt@hitachi.com \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=mtosatti@redhat.com \
    --cc=sebastian@breakpoint.cc \
    --cc=seiji.aguchi@hds.com \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --cc=yoshihiro.yunomae.ez@hitachi.com \
    --cc=yrl.pp-manager.tt@hitachi.com \
    --cc=zhangyanfei@cn.fujitsu.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).