Herbert Xu writes: > It doesn't matter. The memory pressure flag is an *advisory* > flag. If we get it wrong the worst that'll happen is that we'd > waste some time doing work that'll be thrown away.
Ah, so it's the "racy but I don't care because it's only an optimization" case. That's fine. Somehow I find it hard to believe that all the racy uses of atomic_read in the kernel are like that, though. :) > In any case, this actually illustrates why the addition of > volatile is completely pointless. Even if this code was > broken, which it definitely is not, having the volatile > there wouldn't have helped at all. Yes, adding volatile to racy code doesn't somehow make it race-free. Neither does using atomic_t, despite what some seem to believe. I have actually started going through all the uses of atomic_read in the kernel. So far out of the first 100 I have found none where we have two atomic_reads of the same variable and the compiler could usefully use the value from the first as the result of the second. But there's still > 2500 to go... Paul. - 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/
