On Tuesday 07 March 2006 02:52, Benjamin LaHaise wrote: > Those 1-2 cycles are free if you look at how things get scheduled with the > execution of the surrounding code. I bet $20 that you can't find a modern > CPU where the cost is measurable (meaning something like a P4, Athlon). > If this level of cost for the common case is a concern, it's probably worth > making atomic_dec_and_test() inline for page_cache_release(). The overhead > of the function call and the PageCompound() test is probably more than what > we're talking about as you're increasing the cache footprint and actually > performing a write to memory.
The test should be essentially free at least on an out of order CPU. Not quite sure about in order though. -Andi - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
