From: Nick Piggin <piggin@cyberone.com.au>
To: Robert White <rwhite@casabyte.com>
Cc: Rik van Riel <riel@imladris.surriel.com>,
David Woodhouse <dwmw2@infradead.org>,
ptb@it.uc3m.es, William Lee Irwin III <wli@holomorphy.com>,
"Martin J. Bligh" <mbligh@aracnet.com>,
linux-kernel@vger.kernel.org
Subject: Re: recursive spinlocks. Shoot.
Date: Thu, 22 May 2003 14:04:10 +1000 [thread overview]
Message-ID: <3ECC4C3A.9000903@cyberone.com.au> (raw)
In-Reply-To: <PEEPIDHAKMCGHDBJLHKGMEIICMAA.rwhite@casabyte.com>
Robert White wrote:
>>From: Rik van Riel [mailto:riel@surriel.com]On Behalf Of Rik van Riel
>>
>
>>So call_EE_ messes with the data structure which call_ER_
>>has locked, unexpectedly because the recursive locking
>>doesn't show up as an error.
>>
>
>Yes and no. It all hinges on that nonsensical use of "unexpectedly".
>
>(I'll be using fully abstract examples from here on out to prevent the
>function call police from busting me again on a technicality... 8-)
>
Oh come on! Now I won't get into this argument, but you can't win
by saying "if this were implemented in such a way that recursive
locking is required, then recursive locking is required here"!!
Look: I could easily reimplement your snark so it doesn't have to call
the last "whangle" - now see how it can be done completely lockless
with a memory barrier between a and b?
Locking is an implementation issue, and as such I think you'll have
to come up with a real problem or some real code. You must have some
target problem in mind?
Best regards,
Nick
next prev parent reply other threads:[~2003-05-22 3:53 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-18 9:21 recursive spinlocks. Shoot Peter T. Breuer
2003-05-18 16:30 ` Martin J. Bligh
2003-05-18 16:35 ` William Lee Irwin III
2003-05-18 16:49 ` Arjan van de Ven
2003-05-18 16:54 ` William Lee Irwin III
2003-05-18 17:14 ` Martin J. Bligh
2003-05-18 17:24 ` Peter T. Breuer
2003-05-18 22:34 ` David Woodhouse
2003-05-19 13:37 ` Peter T. Breuer
2003-05-19 13:45 ` Jens Axboe
2003-05-19 13:47 ` Arjan van de Ven
[not found] ` <mailman.1053352200.24653.linux-kernel2news@redhat.com>
2003-05-19 23:54 ` Pete Zaitcev
2003-05-20 0:03 ` viro
2003-05-20 0:03 ` Johannes Erdfelt
2003-05-20 3:12 ` Robert White
2003-05-20 11:59 ` Helge Hafting
2003-05-20 12:23 ` Richard B. Johnson
2003-05-20 21:05 ` Robert White
2003-05-20 21:42 ` Richard B. Johnson
2003-05-20 23:06 ` Robert White
2003-05-21 14:01 ` Richard B. Johnson
2003-05-21 21:56 ` Robert White
2003-05-22 0:13 ` viro
2003-05-22 0:32 ` Robert White
2003-05-22 0:46 ` Carl-Daniel Hailfinger
2003-05-21 5:48 ` Nikita Danilov
2003-05-22 1:00 ` Rik van Riel
2003-05-22 3:11 ` Robert White
2003-05-22 4:04 ` Nick Piggin [this message]
2003-05-22 4:42 ` Peter T. Breuer
2003-05-22 5:09 ` Nick Piggin
2003-05-23 0:19 ` Robert White
2003-05-23 7:22 ` Nikita Danilov
2003-05-23 9:07 ` Helge Hafting
2003-05-23 12:18 ` William Lee Irwin III
2003-05-24 2:39 ` Robert White
2003-05-28 16:50 ` Timothy Miller
2003-05-19 2:05 ` Kevin O'Connor
2003-05-19 6:19 ` Jan Hudec
2003-05-19 10:29 ` Helge Hafting
2003-05-19 11:37 ` Nikita Danilov
2003-05-22 1:21 ` Daniel Phillips
2003-05-19 14:28 ` Martin J. Bligh
2003-05-18 18:13 ` Davide Libenzi
[not found] <20030518182010$0541@gated-at.bofh.it>
2003-05-18 19:09 ` Peter T. Breuer
2003-05-18 19:31 ` Davide Libenzi
2003-05-18 19:49 ` Peter T. Breuer
2003-05-18 20:13 ` Davide Libenzi
2003-05-19 20:47 ` Jan Hudec
[not found] <20030518202013$5297@gated-at.bofh.it>
2003-05-18 23:15 ` Peter T. Breuer
2003-05-18 23:26 ` Davide Libenzi
2003-05-19 12:48 ` Peter T. Breuer
2003-05-19 17:15 ` Davide Libenzi
2003-05-19 17:27 ` Peter T. Breuer
2003-05-19 17:57 ` Alan Cox
2003-05-19 19:51 ` Peter T. Breuer
2003-05-19 20:22 ` Robert White
[not found] <20030520231013$3d77@gated-at.bofh.it>
2003-05-21 14:16 ` Peter T. Breuer
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