Andrew Morton <[email protected]> wrote: > and we can assume (and ensure) that a failing test_and_set_bit() will not > write to the affected word at all. You may not assume that; and indeed that is not so in the generic spinlock-based bitops or ARM pre-v6 or PA-RISC or sparc32 or ... Remember: if you have to put a conditional jump in there, it's going to fail one way or the other a certain percentage of the time, and that's going to cause a pipeline stall, and these ops are used quite a lot. OTOH, I don't know that the stall would be that bad since the spin_lock and spin_unlock may cause a stall anyway. David - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] 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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