Re: [PATCH] 2nd try: i386 rw_semaphores fix

From: David Howells (dhowells@cambridge.redhat.com)
Date: Wed Apr 11 2001 - 09:43:48 EST


I've been discussing it with some other kernel and GCC people, and they think
that only "memory" is required.

> What are the reasons against mentioning sem->count directly as a "=m"
> reference? This makes the whole thing less fragile and no more dependent
> on the memory layout of the structure.

Apart from the risk of breaking it, you mean? Well, "=m" seems to reserve an
extra register to hold a second copy of the semaphore address, probably since
it thinks EAX might get clobbered.

Also, as a minor point, it probably ought to be "+m" not "=m".

David
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