On Tue, 2011-05-17 at 23:27 +0200, Ingo Molnar wrote: > * John Stultz <john.stultz@xxxxxxxxxx> wrote: > > > The implicit rules for current->comm access being safe without locking are no > > longer true. Accessing current->comm without holding the task lock may result > > in null or incomplete strings (however, access won't run off the end of the > > string). > > This is rather unfortunate - task->comm is used in a number of performance > critical codepaths such as tracing. > > Why does this matter so much? A NULL string is not a big deal. > > Note, since task->comm is 16 bytes there's the CMPXCHG16B instruction on x86 > which could be used to update it atomically, should atomicity really be > desired. The changelog also fails to mention _WHY_ this is no longer true. Nor does it treat why making it true again isn't an option. Who is changing another task's comm? That's just silly. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href