Re: [ACPI] Re: Linux 2.4.26-rc1 (cmpxchg vs 80386 build)

From: Bill Davidsen
Date: Tue Mar 30 2004 - 15:04:27 EST

Len Brown wrote:
Sorry I didn't reply to this thread, after Alan wrote I figured
the topic was closed;-)

Yes, per my initial message, gcc _will_ generate cmpxchg for the 80386
build. Indeed, it has been doing so for over a year with ACPI's
previous private (and flawed) asm() invocation of cmpxchg.

Andi/Alan suggested we invoke cmpxchg always in ACPI,
but disable ACPI at boot-time in the unlikely event we find
ourselves running on a cpu without that instruction.

Is there no reasonable way to avoid using it in ACPI? It's not as if performance was critical there, or the code gets run often. Too bad it can't just be emulated like floating point, but I don't think it can on SMP.

I have to think Alan is right as usual.

-bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
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