On 12 February 2013 08:03, Ian Lepore <[email protected]> wrote: >> I agree that for practical means, the _currently_ used compilers should >> consider the tsleep() call as the sequential point. But then the volatile >> qualifier cast applied for the given access would not change the code as >> well. >> > > Doesn't this then imply that essentially every driver has this problem, > and for that matter, every sequence of code anywhere in the base > involving "loop while repeatedly sleeping, then waking and checking the > state of some data for changes"? I sure haven't seen that many volatile > qualifiers scattered around the code.
Well, not even that - any cached access (eg to a softc member) after a mutex operation would be invalid. Hence why there's supposed to be some specific fairy dust sprinkled over those functions/inlines to tell the compiler to invalidate local copies of memory structures. Adrian _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
