On Wed, 2011-05-11 at 17:33 +0800, AmÃrico Wang wrote: > On Wed, May 11, 2011 at 8:23 AM, John Stultz <john.stultz@xxxxxxxxxx> wrote: > > Acessing task->comm requires proper locking. However in the past > > access to current->comm could be done without locking. This > > is no longer the case, so all comm access needs to be done > > while holding the comm_lock. > > > > In my attempt to clean up unprotected comm access, I've noticed > > most comm access is done for printk output. To simpify correct > > locking in these cases, I've introduced a new %ptc format, > > which will safely print the corresponding task's comm. > > > > Example use: > > printk("%ptc: unaligned epc - sending SIGBUS.\n", current); > > > > Why do you hide current->comm behide printk? > How is this better than printk("%s: ....", task_comm(current)) ? So to properly access current->comm, you need to hold the task-lock (or with my new patch set, the comm_lock). Rather then adding locking to all the call sites that printk("%s ...", current->comm), I'm suggesting we add a new %ptc method which will handle the locking for you. thanks -john -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>