From: Frederic Weisbecker <[email protected]> When we wait for a zombie task, flush the cputimes on nohz cpusets in case we are waiting for a group leader that has threads running in nohz CPUs. This way thread_group_times() doesn't report stale values.
<doubts> If I understood well the code, by the time we call that thread_group_times(), we may have childs that are still running, so this is necessary. But I need to check deeper. </doubts> Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Alessio Igor Bogani <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Avi Kivity <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Geoff Levand <[email protected]> Cc: Gilad Ben Yossef <[email protected]> Cc: Hakan Akkan <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Kevin Hilman <[email protected]> Cc: Max Krasnyansky <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephen Hemminger <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Sven-Thorsten Dietrich <[email protected]> Cc: Thomas Gleixner <[email protected]> --- kernel/exit.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/exit.c b/kernel/exit.c index 346616c..154c26b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -53,6 +53,7 @@ #include <linux/oom.h> #include <linux/writeback.h> #include <linux/shm.h> +#include <linux/cpuset.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -1634,6 +1635,13 @@ repeat: (!wo->wo_pid || hlist_empty(&wo->wo_pid->tasks[wo->wo_type]))) goto notask; + /* + * For cputime in sub-threads before adding them. + * Must be called outside tasklist_lock lock because write lock + * can be acquired under irqs disabled. + */ + cpuset_nohz_flush_cputimes(); + set_current_state(TASK_INTERRUPTIBLE); read_lock(&tasklist_lock); tsk = current; -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
