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From: Thomas Hood <jdthood@mail.com>
To: unlisted-recipients:; (no To-header on input)@localhost.localdomain
Cc: linux-kernel@vger.kernel.org
Subject: Re: Question about rtc_lock
Date: 06 Oct 2001 10:40:54 -0400	[thread overview]
Message-ID: <1002379256.857.3.camel@thanatos> (raw)
In-Reply-To: <E15prGs-0001G3-00@the-village.bc.nu>
In-Reply-To: <E15prGs-0001G3-00@the-village.bc.nu>

On Sat, 2001-10-06 at 09:13, Alan Cox wrote:
> > No, but what if the rtc interrupts while the lock is held in this
> > bit of code?
> 
> Thats fine. It wont take the lock

But the first line of irq_interrupt() is:
   spin_lock (&rtc_lock);

If one has a multi-processor machine, and CPUx is going through
the bootflag code, which takes the rtc_lock, and that CPU is
interrupted and enters rtc_interrupt(), which tries to take the
rtc_lock, won't it deadlock?

If not, then I'm missing some clue about how these spinlocks work.

Thomas


  reply	other threads:[~2001-10-06 14:41 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-10-06  3:49 Question about rtc_lock Thomas Hood
2001-10-06 13:01 ` Alan Cox
2001-10-06 13:06   ` Thomas Hood
2001-10-06 13:13     ` Alan Cox
2001-10-06 14:40       ` Thomas Hood [this message]
2001-10-06 15:24         ` Jonathan Lundell
2001-10-07  3:24           ` Thomas Hood

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