From: Ingo Molnar <mingo@elte.hu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chuck Ebbert <cebbert@redhat.com>,
Jarek Poplawski <jarkao2@o2.pl>,
Miklos Szeredi <miklos@szeredi.hu>,
chris@atlee.ca, linux-kernel@vger.kernel.org, tglx@linutronix.de,
akpm@linux-foundation.org
Subject: Re: [BUG] long freezes on thinkpad t60
Date: Thu, 21 Jun 2007 22:18:16 +0200 [thread overview]
Message-ID: <20070621201816.GE22303@elte.hu> (raw)
In-Reply-To: <alpine.LFD.0.98.0706211024370.3593@woody.linux-foundation.org>
* Linus Torvalds <torvalds@linux-foundation.org> wrote:
> No, the cache line arbitration doesn't know anything about "locked" vs
> "unlocked" instructions (it could, but there really is no point).
>
> The real issue is that locked instructions on x86 are serializing,
> which makes them extremely slow (compared to just a write), and then
> by being slow they effectively just make the window for another core
> bigger.
>
> IOW, it doesn't "fix" anything, it just hides the bug with timing.
yeah. I think Linux is i think the only OS on the planet that is using
the movb trick for unlock, it even triggered a hardware erratum ;) So it
might surprise some hw makers who might rely on the heuristics that each
critical section lock and unlock is a LOCK-ed instruction.
Ingo
next prev parent reply other threads:[~2007-06-21 20:18 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-24 12:04 [BUG] long freezes on thinkpad t60 Miklos Szeredi
2007-05-24 12:54 ` Ingo Molnar
2007-05-24 14:03 ` Miklos Szeredi
2007-05-24 14:10 ` Ingo Molnar
2007-05-24 14:28 ` Miklos Szeredi
2007-05-24 14:42 ` Ingo Molnar
2007-05-24 14:44 ` Ingo Molnar
2007-05-24 17:09 ` Miklos Szeredi
2007-05-24 21:01 ` Ingo Molnar
2007-05-25 9:51 ` Miklos Szeredi
2007-06-14 16:04 ` Miklos Szeredi
2007-06-15 21:25 ` Chuck Ebbert
2007-06-16 10:37 ` Ingo Molnar
2007-06-17 21:46 ` Miklos Szeredi
2007-06-18 6:43 ` Ingo Molnar
2007-06-18 7:24 ` Miklos Szeredi
2007-06-18 8:12 ` Ingo Molnar
2007-06-18 8:20 ` Andrew Morton
2007-06-19 4:22 ` Ravikiran G Thirumalai
2007-06-18 8:25 ` Miklos Szeredi
2007-06-18 8:31 ` Ingo Molnar
2007-06-18 8:34 ` Miklos Szeredi
2007-06-18 9:18 ` Ingo Molnar
2007-06-18 9:38 ` Ingo Molnar
2007-06-18 9:44 ` Ingo Molnar
2007-06-18 10:18 ` Miklos Szeredi
2007-06-18 12:36 ` Ingo Molnar
2007-06-18 13:10 ` Miklos Szeredi
2007-06-18 16:34 ` Linus Torvalds
2007-06-18 17:41 ` Miklos Szeredi
2007-06-18 17:48 ` Linus Torvalds
2007-06-18 18:02 ` Ingo Molnar
2007-06-18 18:00 ` Ingo Molnar
2007-06-18 18:25 ` Linus Torvalds
2007-06-20 9:36 ` Jarek Poplawski
2007-06-20 17:34 ` Linus Torvalds
2007-06-21 7:30 ` Ingo Molnar
2007-06-21 15:50 ` Linus Torvalds
2007-06-21 16:08 ` Ingo Molnar
2007-06-21 16:32 ` Linus Torvalds
2007-06-21 16:44 ` Chuck Ebbert
2007-06-21 17:31 ` Linus Torvalds
2007-06-21 18:29 ` Eric Dumazet
2007-06-21 18:44 ` Linus Torvalds
2007-06-21 19:35 ` Linus Torvalds
2007-06-21 20:09 ` Ingo Molnar
2007-06-21 20:14 ` Linus Torvalds
2007-06-21 20:30 ` Ingo Molnar
2007-06-21 20:48 ` Linus Torvalds
2007-06-21 21:06 ` Ingo Molnar
2007-06-21 20:42 ` [patch] spinlock debug: make looping nicer Ingo Molnar
2007-06-21 20:58 ` Linus Torvalds
2007-06-21 21:15 ` Ingo Molnar
2007-06-22 7:00 ` Jarek Poplawski
2007-06-21 20:36 ` [BUG] long freezes on thinkpad t60 Eric Dumazet
2007-06-21 19:56 ` Ingo Molnar
2007-06-21 20:10 ` Linus Torvalds
2007-06-21 20:23 ` Ingo Molnar
2007-06-21 20:12 ` Ingo Molnar
2007-06-26 8:42 ` Nick Piggin
2007-06-26 10:56 ` Jarek Poplawski
2007-06-26 17:23 ` Linus Torvalds
2007-06-27 5:23 ` Nick Piggin
2007-06-27 6:04 ` Linus Torvalds
2007-06-27 6:20 ` Nick Piggin
2007-06-27 19:47 ` Linus Torvalds
2007-06-27 20:10 ` Ingo Molnar
2007-06-27 20:17 ` Davide Libenzi
2007-06-27 22:11 ` Linus Torvalds
2007-06-27 23:30 ` Davide Libenzi
2007-06-28 0:46 ` Linus Torvalds
2007-06-28 3:03 ` Davide Libenzi
2007-07-02 7:06 ` Nick Piggin
2007-06-21 20:16 ` Ingo Molnar
2007-06-22 8:17 ` Ingo Molnar
2007-06-23 10:36 ` Miklos Szeredi
2007-06-23 16:39 ` Linus Torvalds
2007-06-25 6:45 ` Jarek Poplawski
2007-06-21 20:18 ` Ingo Molnar [this message]
2007-06-21 20:36 ` Linus Torvalds
2007-06-21 7:38 ` Jarek Poplawski
2007-06-21 8:39 ` Ingo Molnar
2007-06-21 11:09 ` Jarek Poplawski
2007-06-21 16:01 ` Linus Torvalds
2007-06-22 10:38 ` Jarek Poplawski
2007-05-24 22:08 ` Henrique de Moraes Holschuh
2007-05-24 22:13 ` Kok, Auke
2007-05-25 6:58 ` Ingo Molnar
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=20070621201816.GE22303@elte.hu \
--to=mingo@elte.hu \
--cc=akpm@linux-foundation.org \
--cc=cebbert@redhat.com \
--cc=chris@atlee.ca \
--cc=jarkao2@o2.pl \
--cc=linux-kernel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.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;
as well as URLs for NNTP newsgroup(s).