All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@elte.hu>
To: Andi Kleen <andi@firstfloor.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Jack Steiner <steiner@sgi.com>, Jan Beulich <JBeulich@novell.com>,
	Borislav Petkov <bp@amd64.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Nick Piggin <npiggin@kernel.dk>,
	"x86@kernel.org" <x86@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@redhat.com>,
	tee@sgi.com, Nikanth Karthikesan <knikanth@suse.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible
Date: Fri, 25 Mar 2011 20:26:01 +0100	[thread overview]
Message-ID: <20110325192601.GC22960@elte.hu> (raw)
In-Reply-To: <20110325172217.GP21838@one.firstfloor.org>


* Andi Kleen <andi@firstfloor.org> wrote:

> > Could you please try the patch below?
> 
> This is very likely not a good idea.  I heard some systems can hang
> if you overwrite their PMUs this way and you're unlucky enough :-(

Wrong - in that case all kernels from 2.6.32 to 2.6.38 would already be locking 
up. This patch simply restores behavior to essentially what it was before 
v2.6.38 - but also adds the warning.

Thanks,

	Ingo

  reply	other threads:[~2011-03-25 19:26 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-24  4:56 [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible Nikanth Karthikesan
2011-03-24  8:52 ` Jan Beulich
2011-03-24  8:56 ` Ingo Molnar
2011-03-24 14:52   ` Borislav Petkov
2011-03-24 16:48     ` Jan Beulich
2011-03-24 17:19       ` Ingo Molnar
2011-03-25 10:06         ` Jan Beulich
2011-03-25 11:10           ` Ingo Molnar
2011-03-25 12:04             ` Nikanth Karthikesan
2011-03-25 13:12           ` Jack Steiner
2011-03-25 16:29           ` Linus Torvalds
2011-03-25 16:47             ` Jan Beulich
2011-03-25 16:49             ` Jack Steiner
2011-03-24 17:30       ` Jack Steiner
2011-03-24 20:00         ` Ingo Molnar
2011-03-24 20:40           ` Andi Kleen
2011-03-24 20:50             ` Ingo Molnar
2011-03-24 21:37               ` Andi Kleen
2011-03-24 20:48           ` Eric Dumazet
2011-03-24 20:54             ` Ingo Molnar
2011-03-24 21:02               ` Eric Dumazet
2011-03-24 21:42                 ` Andi Kleen
2011-03-24 23:26                   ` Linus Torvalds
2011-03-24 23:56                     ` Andi Kleen
2011-03-25  5:47                       ` Eric Dumazet
2011-03-25  9:32                         ` Ingo Molnar
2011-03-25  9:44                           ` Eric Dumazet
2011-03-25  9:59                             ` Ingo Molnar
2011-03-25 10:50                               ` Borislav Petkov
2011-03-25 11:10                               ` Peter Zijlstra
2011-03-25 11:11                                 ` Ingo Molnar
2011-03-25 16:16                           ` Robert Richter
2011-03-25 17:22                           ` Andi Kleen
2011-03-25 19:26                             ` Ingo Molnar [this message]
2011-03-25  9:38                         ` Eric Dumazet
2011-03-25 20:29                           ` Peter Zijlstra
2011-03-26  8:15                             ` Eric Dumazet
2011-03-26  9:44                               ` Peter Zijlstra
2011-03-26  9:57                               ` Ingo Molnar
2011-03-25  9:22                       ` Ingo Molnar
2011-03-25 10:21                         ` Peter Zijlstra
2011-03-25 16:08                           ` Robert Richter
2011-03-25 19:31                             ` Ingo Molnar
2011-03-25 17:15                           ` Andi Kleen
2011-03-25 19:21                             ` Ingo Molnar
2011-03-25  9:35                     ` Ingo Molnar
2011-03-24 17:01 ` Linus Torvalds
2011-03-24 17:13 ` Jack Steiner
2011-03-24 18:38 ` Andi Kleen

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=20110325192601.GC22960@elte.hu \
    --to=mingo@elte.hu \
    --cc=JBeulich@novell.com \
    --cc=a.p.zijlstra@chello.nl \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=bp@amd64.org \
    --cc=eric.dumazet@gmail.com \
    --cc=hpa@zytor.com \
    --cc=knikanth@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=npiggin@kernel.dk \
    --cc=steiner@sgi.com \
    --cc=tee@sgi.com \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.