Hello, Kent. On Mon, Jan 28, 2013 at 01:45:06PM -0800, Kent Overstreet wrote: > Ahh. Bias value sounds... hacky (i.e. harder to convince myself it's > correct) but I see what you're getting at.
I don't think it's that hacky. Just push the base point to the opposite of zero - LLONG_MAX. The global counter can start biased so that it gets unbiased only once dying is confirmed and everything can blindly do atomic64_dec_and_test() and trust the result. > Something to consider is wrapping; after we set state to dying but > before we've collected the percpu counters, the atomic counter may be > negative. There's a reason why we use 64bit vars for this type of global counting. They virtually don't wrap. Here, you'll need 1<<63 for the counter to unintentionally reach 0, which we consider practically impossible. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
