From: Linus Torvalds <torvalds@linux-foundation.org>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel@vger.kernel.org
Subject: Re: floppy driver assumes INITIAL_JIFFIES == 0
Date: Thu, 3 Jun 2010 16:09:12 -0700 (PDT) [thread overview]
Message-ID: <alpine.LFD.2.00.1006031606040.8175@i5.linux-foundation.org> (raw)
In-Reply-To: <20100603155414.6ebd1d78@nehalam>
On Thu, 3 Jun 2010, Stephen Hemminger wrote:
>
> Thank you for confirming my suspicions. Given the state of destruction
> there, bug fixing is like playing Jenga.
I suspect it's fixable, but it would probably involve a lot of careful
moving around of that "floppy_lock" spinlock. Add various asserts to make
sure that it's held in all cases, and then for each warning you get, you
add the proper spinlock until it's all properly protected.
The _original_ protection was just from irqs being atomic (UP, remember),
and the block layer queueing happening from irq-safe context. You're still
running it on UP, but we've even lost the irq-handler protection (and then
later, the bottom-half mutual exclusion).
Linus
next prev parent reply other threads:[~2010-06-03 23:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-03 17:15 Stephen Hemminger
2010-06-03 17:28 ` Linus Torvalds
2010-06-03 19:03 ` Stephen Hemminger
2010-06-03 19:56 ` Linus Torvalds
2010-06-03 20:59 ` Linus Torvalds
2010-06-03 21:49 ` Stephen Hemminger
2010-06-03 21:58 ` Linus Torvalds
2010-06-03 22:33 ` Linus Torvalds
2010-06-03 22:54 ` Stephen Hemminger
2010-06-03 23:09 ` Linus Torvalds [this message]
2010-06-03 23:15 ` Stephen Hemminger
2010-06-03 23:21 ` Linus Torvalds
2010-06-09 5:32 ` Stephen Hemminger
2010-06-03 22:32 ` Andreas Mohr
2010-06-03 22:40 ` Linus Torvalds
2010-06-04 15:12 ` Nick Bowler
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