[parisc-linux] init_idle and local_irq_save
Matthew Wilcox
willy at debian.org
Mon Mar 29 09:31:34 MST 2004
On Mon, Mar 29, 2004 at 09:03:57AM -0700, Grant Grundler wrote:
> o double_rq_lock() acquires the locks with lowest address first.
> double_rq_unlock() does not release those in the inverse order.
> Is that a problem?
No. You have two possibilities (locks A, B; acquire and release):
1. Aa Ba Ar Br
2. Aa Ba Br Ar
It doesn't matter how you combine them; either you are waiting for A or
you have A and are waiting for B. You never have B and are waiting for A.
Case 2 is the more common idiom since B is then entirely nested within A,
but lock A ranks lock B in both cases, so you're safe.
--
"Next the statesmen will invent cheap lies, putting the blame upon
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince
himself that the war is just, and will thank God for the better sleep
he enjoys after this process of grotesque self-deception." -- Mark Twain
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