* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 18 May 2011 08:25:54 +0200 Ingo Molnar <mingo@xxxxxxx> wrote: > > > " Hey, this looks a bit racy and 'top' very rarely, on rare workloads that > > play with ->comm[], might display a weird reading task name for a second, > > amongst the many other temporarily nonsensical statistical things it > > already prints every now and then. " > > Well we should at least make sure that `top' won't run off the end of comm[] > and go oops. I think that's guaranteed by the fact(s) that init_tasks's > comm[15] is zero and is always copied-by-value across fork and can never be > overwritten in any task_struct. Correct. > But I didn't check that. I actually have a highly threaded app that uses PR_SET_NAME heavily and would have noticed any oopsing potential long ago. Since ->comm is often observed from other tasks, regardless whether it's set from the prctl() or from the newfangled /proc vector, the race for seeing partial updates to ->comm always existed - for more than 10 years. So the premise of the whole series is wrong: temporarily incomplete ->comm[]s were *always* possible and did not start 1.5+ years ago with: 4614a696bd1c: procfs: allow threads to rename siblings via /proc/pid/tasks/tid/comm when i see series being built on a fundamentally wrong premise i get a bit sad! Thanks, Ingo -- 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>