3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mateusz Guzik <mguzik@xxxxxxxxxx> commit b0ab99e7736af88b8ac1b7ae50ea287fffa2badc upstream. proc_sched_show_task() does: if (nr_switches) do_div(avg_atom, nr_switches); nr_switches is unsigned long and do_div truncates it to 32 bits, which means it can test non-zero on e.g. x86-64 and be truncated to zero for division. Fix the problem by using div64_ul() instead. As a side effect calculations of avg_atom for big nr_switches are now correct. Signed-off-by: Mateusz Guzik <mguzik@xxxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1402750809-31991-1-git-send-email-mguzik@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/sched/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -551,7 +551,7 @@ void proc_sched_show_task(struct task_st avg_atom = p->se.sum_exec_runtime; if (nr_switches) - do_div(avg_atom, nr_switches); + avg_atom = div64_ul(avg_atom, nr_switches); else avg_atom = -1LL; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html