On Sat, 5 Apr 2008, Andrea Arcangeli wrote: > > + rcu_assign_pointer(mm->emm_notifier, e); > > + mm_unlock(mm); > > My mm_lock solution makes all rcu serialization an unnecessary > overhead so you should remove it like I already did in #v11. If it > wasn't the case, then mm_lock wouldn't be a definitive fix for the > race.
There still could be junk in the cache of one cpu. If you just read the new pointer but use the earlier content pointed to then you have a problem. So a memory fence / barrier is needed to guarantee that the contents pointed to are fetched after the pointer. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Register now and save $200. Hurry, offer ends at 11:59 p.m., Monday, April 7! Use priority code J8TLD2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
