On Fri, 2007-08-17 at 12:50 -0600, Chris Friesen wrote: > Linus Torvalds wrote: > > > - in other words, the *only* possible meaning for "volatile" is a purely > > single-CPU meaning. And if you only have a single CPU involved in the > > process, the "volatile" is by definition pointless (because even > > without a volatile, the compiler is required to make the C code appear > > consistent as far as a single CPU is concerned). > > I assume you mean "except for IO-related code and 'random' values like > jiffies" as you mention later on? I assume other values set in > interrupt handlers would count as "random" from a volatility perspective? > > > So anybody who argues for "volatile" fixing bugs is fundamentally > > incorrect. It does NO SUCH THING. By arguing that, such people only show > > that you have no idea what they are talking about. > > What about reading values modified in interrupt handlers, as in your > "random" case? Or is this a bug where the user of atomic_read() is > invalidly expecting a read each time it is called?
the interrupt handler case is an SMP case since you do not know beforehand what cpu your interrupt handler will run on. - 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/
