diff options
Diffstat (limited to 'features/rt/sched-Disable-TTWU_QUEUE-on-RT.patch')
| -rw-r--r-- | features/rt/sched-Disable-TTWU_QUEUE-on-RT.patch | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/features/rt/sched-Disable-TTWU_QUEUE-on-RT.patch b/features/rt/sched-Disable-TTWU_QUEUE-on-RT.patch new file mode 100644 index 00000000..d8a5054d --- /dev/null +++ b/features/rt/sched-Disable-TTWU_QUEUE-on-RT.patch @@ -0,0 +1,37 @@ +From 1b8c8ade10b0b08dd7f7c2068683a78571967037 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Tue, 13 Sep 2011 16:42:35 +0200 +Subject: [PATCH 123/191] sched: Disable TTWU_QUEUE on RT + +The queued remote wakeup mechanism can introduce rather large +latencies if the number of migrated tasks is high. Disable it for RT. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +--- + kernel/sched/features.h | 5 +++++ + 1 file changed, 5 insertions(+) + +diff --git a/kernel/sched/features.h b/kernel/sched/features.h +index 1bc2b158fc51..b47967d00570 100644 +--- a/kernel/sched/features.h ++++ b/kernel/sched/features.h +@@ -46,11 +46,16 @@ SCHED_FEAT(DOUBLE_TICK, false) + */ + SCHED_FEAT(NONTASK_CAPACITY, true) + ++#ifdef CONFIG_PREEMPT_RT ++SCHED_FEAT(TTWU_QUEUE, false) ++#else ++ + /* + * Queue remote wakeups on the target CPU and process them + * using the scheduler IPI. Reduces rq->lock contention/bounces. + */ + SCHED_FEAT(TTWU_QUEUE, true) ++#endif + + /* + * When doing wakeups, attempt to limit superfluous scans of the LLC domain. +-- +2.19.1 + |