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Willy Tarreau wrote: > On Sat, Aug 30, 2003 at 08:27:44AM +0200, Antonio Vargas wrote: > > That was my fault for introducing an exchange instruction > > into an assignement discussion, but I don't know of any > > x86 instruction which can load 64bits to memory atomically, > > is there any??? > > perhaps "pusha", but it will load fare more than you need, and I don't know > if it's lockable. "pusha" does not promise 64 bit writes. It can't be interrupted, but I see nothing that ensures the multiple 32 bit words are combined into atomic 64 bit writes as seen by other CPUs or peripherals. > Some MMX instruction might do it too, although not sure. Yes, if you want a 64 bit write and don't want to use cmpxchg8b, MMX will do it. You can also do it with the floating-point "fistpll" instruction (also called "fistpq"). -- Jamie - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
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