On Sun, 24 Feb 2008, Rafael J. Wysocki wrote: > > Very subtly wrong ;-). > > > > imagine suspending_task == 0xabcdef01. Now task "R" with current == > > 0xabcd0000 reads suspending_task while the other cpu is writing to it, > > and sees 0xabcd0000 (0xef01 was not yet written) -- and mistakenly > > believes that "R" == suspending_task. > > > > I agree it is very unlikely, and it will not happen on i386. But what > > about just using atomic_t suspending_task, and store current->pid into > > it? > > I'd rather use a lock, frankly. For example, we can require the readers to > take pm_sleep_rwsem for reading in order to access that.
That certainly won't work. Imagine what would happen when the reader _was_ the suspending task. But if you really twist my arm, I'll go along with Pavel's suggestion. Alan Stern -- 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/
