On Wed, 08 Aug 2007 02:47:53 -0400 Chris Snook <[EMAIL PROTECTED]> wrote:
> Chris Friesen wrote: > > Chris Snook wrote: > > > >> This is not a problem, since indirect references will cause the CPU to > >> fetch the data from memory/cache anyway. > > > > Isn't Zan's sample code (that shows the problem) already using indirect > > references? > > Yeah, I misinterpreted his conclusion. I thought about this for a > while, and realized that it's perfectly legal for the compiler to re-use > a value obtained from atomic_read. All that matters is that the read > itself was atomic. The use (or non-use) of the volatile keyword is Sorry, I can't understand it a bit .., Could you do in detail? -- Jerry > really more relevant to the other atomic operations. If you want to > guarantee a re-read from memory, use barrier(). This, incidentally, > uses volatile under the hood. > > -- Chris - 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/
