diff options
author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-11-13 13:32:29 -0500 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2010-11-18 07:27:46 -0500 |
commit | 48c5ccae88dcd989d9de507e8510313c6cbd352b (patch) | |
tree | 06fe8ce2ac28e9f5844de8bc32ecbef97e40d68b /include | |
parent | 92fd4d4d67b945c0766416284d4ab236b31542c4 (diff) |
sched: Simplify cpu-hot-unplug task migration
While discussing the need for sched_idle_next(), Oleg remarked that
since try_to_wake_up() ensures sleeping tasks will end up running on a
sane cpu, we can do away with migrate_live_tasks().
If we then extend the existing hack of migrating current from
CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the
need for the sched_idle_next() abomination disappears as well, since
idle will be the only possible thread left after the migration thread
stops.
This greatly simplifies the hot-unplug task migration path, as can be
seen from the resulting code reduction (and about half the new lines
are comments).
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1289851597.2109.547.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/sched.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 3cd70cf91fde..29d953abb5ad 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h | |||
@@ -1871,14 +1871,11 @@ extern void sched_clock_idle_sleep_event(void); | |||
1871 | extern void sched_clock_idle_wakeup_event(u64 delta_ns); | 1871 | extern void sched_clock_idle_wakeup_event(u64 delta_ns); |
1872 | 1872 | ||
1873 | #ifdef CONFIG_HOTPLUG_CPU | 1873 | #ifdef CONFIG_HOTPLUG_CPU |
1874 | extern void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p); | ||
1875 | extern void idle_task_exit(void); | 1874 | extern void idle_task_exit(void); |
1876 | #else | 1875 | #else |
1877 | static inline void idle_task_exit(void) {} | 1876 | static inline void idle_task_exit(void) {} |
1878 | #endif | 1877 | #endif |
1879 | 1878 | ||
1880 | extern void sched_idle_next(void); | ||
1881 | |||
1882 | #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) | 1879 | #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) |
1883 | extern void wake_up_idle_cpu(int cpu); | 1880 | extern void wake_up_idle_cpu(int cpu); |
1884 | #else | 1881 | #else |