In the continuining discussion about how GCC treats the volatile keyword, Linus Torvalds noted, "I just have a strong suspicion that 'volatile' performance is so low down the list of any C compiler persons interest, that it's never going to happen. And quite frankly, I cannot blame the gcc guys for it." He went on to explain, "that's especially as 'volatile' really isn't a very good feature of the C language, and is likely to get *less* interesting rather than more (as user space starts to be more and more threaded, 'volatile' gets less and less useful."

"So I wouldn't expect 'volatile' to ever really generate better code. It might happen as a side effect of other improvements (eg, I might hope that the SSA work would eventually lead to gcc having a much better defined model of valid optimizations, and maybe better code generation for volatile accesses fall out cleanly out of that), but in the end, it's such an ugly special case in C, and so seldom used, that I wouldn't depend on it.

"Quite frankly, I'd like there to be more competition in the open source compiler game, and that might cause some upheavals, but on the whole, gcc actually does a pretty damn good job."

"People who think 'volatile' really matters are just fooling themselves," Linus Torvalds quipped during a lengthy discussion on the Linux Kernel mailing list. The thread began with a series of patches to "make atomic_read() behave consistently across all architectures" which included "removing the volatile keyword from all atomic_t and atomic64_t definitions that currently have it, and instead explicitly [casting] the variable as volatile in atomic_read()."

Earlier in the discussion Linus had suggested that while it didn't actually fix any bugs it did help hide bugs and make them less likely to be triggered, "and hey, sometimes 'hiding bugs well enough' is ok. In this case, I'd argue that we've successfully *not* had the volatile there for eight months on x86-64, and that should tell people something. " But later in the discussion he related it to superstitions like the fear of a black cat crossing the road, which "has no bigger and longer-lasting direct affects":

"In other words, this whole discussion has just convinced me that we should *not* add back 'volatile' to 'atomic_read()' - I was willing to do it for practical and 'hide the bugs' reasons, but having seen people argue for it, thinking that it actually fixes something, I'm now convinced that the *last* thing we should do is to encourage that kind of superstitious thinking."