From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Lee Irwin III Date: Thu, 19 Aug 2004 15:00:08 +0000 Subject: Re: Patch - Sun4d SMP now boots Message-Id: <20040819150008.GO11200@holomorphy.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org On Thursday 19 August 2004 3:12 pm, William Lee Irwin III 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... On Thu, Aug 19, 2004 at 03:49:18PM +0100, C.Newport wrote: > 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. Sounds like the analogous rewrite must happen for sun4d, then. I'll look into that... some kind of sun4d hacking-level access may need to happen, or someone may have to look into this on my behalf. -- wli