public inbox for linux-acpi@vger.kernel.org
 help / color / mirror / Atom feed
From: Maxim Levitsky <maximlevitsky@gmail.com>
To: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Len Brown <len.brown@intel.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Yong Zhang <yong.zhang0@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
	Andy Grover <andy.grover@oracle.com>
Subject: Re: [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and touch_softlockup_watchdog
Date: Thu, 26 Aug 2010 13:14:31 +0300	[thread overview]
Message-ID: <1282817671.4338.0.camel@maxim-laptop> (raw)
In-Reply-To: <20100820025749.GB4879@redhat.com>

On Thu, 2010-08-19 at 22:57 -0400, Don Zickus wrote: 
> On Wed, Aug 18, 2010 at 01:01:56PM -0700, Andrew Morton wrote:
> > The surprise new requirement that touch_nmi_watchdog() be called from
> > non-preemptible code does seem to make sense IMO.  It's hard to see why
> > anyone would be touching the watchdog unless he's spinning in irqs-off
> > code.  Except, of course, when we have a utility function which can be
> > called from wither irqs-on or irqs-off: acpi_os_stall().
> > 
> > That being said, it's not good to introduce new API requirements by
> > accident!  An audit of all callers should first be performed, at least.
> > 
> > 
> > The surprise new requirement that touch_softlockup_watchdog() be called
> > from non-preemptible code doesn't make sense IMO.  If I have a piece of
> > code in the kernel which I expect to sit in TASK_UNINTERRUPTIBLE state
> > for three minutes waiting for my egg to boil, I should be able to do
> > that and I should be able to touch the softlockup detector without
> > needing to go non-preemptible.
> 
> Ok, so here is my patch that syncs the touch_*_watchdog back in line with
> the old semantics.  Hopefully this will undo any harm I caused.

Was this patch forgotten?

Best regards,
Maxim Levitsky


  parent reply	other threads:[~2010-08-26 10:14 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1281966418.1926.1421.camel@laptop>
     [not found] ` <20100816140829.GA5225@swordfish.minsk.epam.com>
     [not found]   ` <20100817025954.GA12366@nowhere>
     [not found]     ` <AANLkTikdng247Fct0ANXiitC3ja98_ee3-fUVDGraEwo@mail.gmail.com>
     [not found]       ` <20100817083945.GA12022@swordfish.minsk.epam.com>
     [not found]         ` <AANLkTik-4S_=L5FLhMfommf5Umd0xO+h4QP9uoxwrgFE@mail.gmail.com>
     [not found]           ` <20100817092407.GB12022@swordfish.minsk.epam.com>
     [not found]             ` <AANLkTikjR1nC3DYdvSw=FEmAVZ98=ju2RNq-MF1L7U3u@mail.gmail.com>
     [not found]               ` <20100817103948.GA5352@swordfish.minsk.epam.com>
     [not found]                 ` <20100817131320.GX4879@redhat.com>
     [not found]                   ` <20100818024802.GA24748@nowhere>
2010-08-18 20:01                     ` [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and touch_softlockup_watchdog Andrew Morton
2010-08-19  2:27                       ` Don Zickus
2010-08-20  2:57                       ` Don Zickus
2010-08-20  3:42                         ` Andrew Morton
2010-08-20 12:34                           ` Don Zickus
2010-08-26 17:17                           ` acpi_os_stall() and touch_nmi_watchdog() (was Re: [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and touch_softlockup_watchdog) Len Brown
2010-08-20 15:02                         ` [PATCH] fix BUG using smp_processor_id() in touch_nmi_watchdog and touch_softlockup_watchdog Yong Zhang
2010-08-26 10:14                         ` Maxim Levitsky [this message]
2010-08-26 14:40                           ` Don Zickus

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=1282817671.4338.0.camel@maxim-laptop \
    --to=maximlevitsky@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=andy.grover@oracle.com \
    --cc=dzickus@redhat.com \
    --cc=fweisbec@gmail.com \
    --cc=len.brown@intel.com \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=peterz@infradead.org \
    --cc=sergey.senozhatsky@gmail.com \
    --cc=yong.zhang0@gmail.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