From: "C.Newport" <crn@netunix.com>
To: sparclinux@vger.kernel.org
Subject: Re: Patch - Sun4d SMP now boots
Date: Thu, 19 Aug 2004 14:49:18 +0000 [thread overview]
Message-ID: <200408191549.18157.crn@netunix.com> (raw)
In-Reply-To: <Pine.LNX.4.53.0408191358400.2910@mailgate.netunix.com>
On Thursday 19 August 2004 3:12 pm, William Lee Irwin III wrote:
> On Thu, Aug 19, 2004 at 02:32:47PM +0100, Chris Newport wrote:
> One major question is *WHY* spin_lock_bh() vs. spin_lock_irqsave()
> works. Only trouble there is that we can't see what happens after
> spin_lock_irqsave() very easily. One rather large possibility is that
> since disabling bh's doesn't disable interrupts, some smp_call_function()
> or similar that would deadlock if interrupts weren't disabled suddenly
> appears to work and/or works for some limited cases...
Two possible clues :-
Other architectures have 2 sets of functions here, one for use before it is
safe to allow SMP with IRQs.
sun4d_irq.c is almost certainly involved, and does not appear to deal with
SMP in a sane manner. Compare with sun4m_irq.c which is much newer.
This is consistent with the observed failure, the system locks as soon as
a write to disk happens. Pasi also noted failures as soon as interrupts
happen.
next prev parent reply other threads:[~2004-08-19 14:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-19 13:32 Patch - Sun4d SMP now boots Chris Newport
2004-08-19 14:12 ` William Lee Irwin III
2004-08-19 14:33 ` David S. Miller
2004-08-19 14:49 ` C.Newport [this message]
2004-08-19 15:00 ` William Lee Irwin III
2004-08-19 15:22 ` C.Newport
2004-08-19 15:29 ` William Lee Irwin III
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