Re: [PATCH 1/12]: MUTEX: Implement mutexes

[Russell King]

On Sat, Dec 17, 2005 at 12:11:39PM -0800, Linus Torvalds wrote:
> Of the other architectures you list, only ARM is really important. And no, 
> arm doesn't do swap. It does LL/SC (except they call it "ldrex/strex", 
> which I assume stands for "load/store with reservation and X just because 
> X is cool. Yeah, we're cool" (*)).

> (*) Actually, some arm docs I found implies that "ex" stands for 
> "exclusive", but that leaves me wondering what the "r" stands for? 

FYI.  The standard instructions:

ldr = load register
str = store register

The new (ARM architecture v6 and above) atomic instructions:

ldrex = load register exclusive
strex = store register exclusive

Previous architecture versions only have the 32-bit and 8 bit
unconditional swap instructions.  Luckily they're unlikely to be
used for SMP in the field.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core
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