From: Pavel Machek <pavel@ucw.cz>
To: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Albert Cahalan <acahalan@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: 2048 CPUs [was: Re: New filesystem for Linux]
Date: Sun, 12 Nov 2006 14:28:13 +0000 [thread overview]
Message-ID: <20061112142813.GA4371@ucw.cz> (raw)
In-Reply-To: <Pine.LNX.4.64.0611101606090.20654@artax.karlin.mff.cuni.cz>
Hi!
> >>You can't tell that CPUs behave exactly
> >>probabilistically --- it may
> >>happen that one gets out of the wait loop always too
> >>late.
> >
> >Well, I don't need them to be _exactly_
> >probabilistical.
> >
> >Anyway, if you have 2048 CPUs... you can perhaps get
> >some non-broken
> >ones.
>
> No intel document guarantees you that if more CPUs
> simultaneously execute locked cmpxchg in a loop that a
If we are talking 2048 cpus, we are talking ia64.
> CPU will see compare success in a finite time. In fact,
> CPUs can't guarantee this at all, because they don't
> know that they're executing a spinlock --- for them its
> just an instruction stream like anything else.
...even i386 has monitor/mwait these days.
Pavel
--
Thanks for all the (sleeping) penguins.
next prev parent reply other threads:[~2006-11-12 18:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <787b0d920611041154l69db46abv4c8c467809ada57c@mail.gmail.com>
2006-11-04 22:36 ` 2048 CPUs [was: Re: New filesystem for Linux] Mikulas Patocka
[not found] ` <787b0d920611050802o460a4000r5ce154e589732a02@mail.gmail.com>
2006-11-06 1:47 ` Mikulas Patocka
2006-11-07 21:26 ` Pavel Machek
2006-11-07 22:36 ` Mikulas Patocka
2006-11-07 23:14 ` Pavel Machek
2006-11-08 18:26 ` Mikulas Patocka
2006-11-10 9:03 ` Pavel Machek
2006-11-10 15:20 ` Mikulas Patocka
2006-11-10 16:20 ` Alan Cox
2006-11-12 14:28 ` Pavel Machek [this message]
2006-11-12 20:07 ` Mikulas Patocka
2006-11-14 6:24 ` Albert Cahalan
2006-11-08 3:04 ` David Chinner
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