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From: Michael Schnell <mschnell@lumino.de>
To: unlisted-recipients:; (no To-header on input)
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	nios2-dev <nios2-dev@sopc.et.ntust.edu.tw>
Subject: Re: atomic RAM ?
Date: Fri, 09 Apr 2010 12:54:26 +0200	[thread overview]
Message-ID: <4BBF0762.8040505@lumino.de> (raw)
In-Reply-To: <201004081615.01151.arnd@arndb.de>

On 04/08/2010 04:15 PM, Arnd Bergmann wrote:
> /* returns one if we got the lock, zero if someone else holds it */
> bool hashlock_addr(volatile void *addr);
>   
I don't see how (to do FUTEX) a hashlock can be implemented in a way
that we stay in user mode when locking it and - if it's already locked -
we do a Kernel call for waiting on it being unlocked by another thread.
(This is what FUTEX does.)

-Michael

  reply	other threads:[~2010-04-09 10:54 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-08  7:32 atomic RAM ? Michael Schnell
     [not found] ` <4BBDA1CB.3070204@davidnewall.com>
2010-04-08  9:52   ` Michael Schnell
2010-04-12 12:54     ` Pavel Machek
2010-04-14  8:42       ` Michael Schnell
     [not found] ` <k2gbca41b4c1004080243nc45a10aereaae18557808c943@mail.gmail.com>
2010-04-08 10:12   ` Michael Schnell
2010-04-08 10:45 ` Alan Cox
2010-04-08 12:11   ` Michael Schnell
2010-04-08 12:14     ` David Miller
2010-04-08 12:30       ` Michael Schnell
2010-04-08 14:15         ` Arnd Bergmann
2010-04-09 10:54           ` Michael Schnell [this message]
     [not found]           ` <4BBEECC8.10005@lumino.de>
     [not found]             ` <201004091714.04990.arnd@arndb.de>
2010-04-12  9:58               ` Michael Schnell
2010-04-12 15:02                 ` Arnd Bergmann
2010-04-13 10:11                   ` Michael Schnell
     [not found]                 ` <u2j42b5547a1004120845x87d7f2f7wd4acea1144153dd6@mail.gmail.com>
2010-04-13  8:39                   ` [Nios2-dev] " Michael Schnell
2010-04-08 13:37     ` Alan Cox
2010-04-09 10:55       ` Michael Schnell
2010-04-09 11:54         ` Alan Cox
2010-04-09 12:53           ` Michael Schnell
2010-04-09 13:15             ` Alan Cox
2010-04-09 13:14               ` Michael Schnell
2010-04-09 13:32               ` Michael Schnell
2010-04-14 12:46       ` Michael Schnell
2010-04-14 12:57         ` Alan Cox
2010-04-14 14:38           ` Michael Schnell
2010-04-09  1:36 ` Mike Frysinger
2010-04-09  9:23   ` Michael Schnell

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