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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-22 15:52:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-22 15:52:04 -0700
commit23b7776290b10297fe2cae0fb5f166a4f2c68121 (patch)
tree73d1e76644a20bc7bff80fbfdb08e8b9a9f28420 /kernel/locking
parent6bc4c3ad3619e1bcb4a6330e030007ace8ca465e (diff)
parent6fab54101923044712baee429ff573f03b99fc47 (diff)
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: "The main changes are: - lockless wakeup support for futexes and IPC message queues (Davidlohr Bueso, Peter Zijlstra) - Replace spinlocks with atomics in thread_group_cputimer(), to improve scalability (Jason Low) - NUMA balancing improvements (Rik van Riel) - SCHED_DEADLINE improvements (Wanpeng Li) - clean up and reorganize preemption helpers (Frederic Weisbecker) - decouple page fault disabling machinery from the preemption counter, to improve debuggability and robustness (David Hildenbrand) - SCHED_DEADLINE documentation updates (Luca Abeni) - topology CPU masks cleanups (Bartosz Golaszewski) - /proc/sched_debug improvements (Srikar Dronamraju)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits) sched/deadline: Remove needless parameter in dl_runtime_exceeded() sched: Remove superfluous resetting of the p->dl_throttled flag sched/deadline: Drop duplicate init_sched_dl_class() declaration sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target sched/deadline: Make init_sched_dl_class() __init sched/deadline: Optimize pull_dl_task() sched/preempt: Add static_key() to preempt_notifiers sched/preempt: Fix preempt notifiers documentation about hlist_del() within unsafe iteration sched/stop_machine: Fix deadlock between multiple stop_two_cpus() sched/debug: Add sum_sleep_runtime to /proc/<pid>/sched sched/debug: Replace vruntime with wait_sum in /proc/sched_debug sched/debug: Properly format runnable tasks in /proc/sched_debug sched/numa: Only consider less busy nodes as numa balancing destinations Revert 095bebf61a46 ("sched/numa: Do not move past the balance point if unbalanced") sched/fair: Prevent throttling in early pick_next_task_fair() preempt: Reorganize the notrace definitions a bit preempt: Use preempt_schedule_context() as the official tracing preemption point sched: Make preempt_schedule_context() function-tracing safe x86: Remove cpu_sibling_mask() and cpu_core_mask() x86: Replace cpu_**_mask() with topology_**_cpumask() ...
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/lglock.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/locking/lglock.c b/kernel/locking/lglock.c
index 86ae2aebf004..951cfcd10b4a 100644
--- a/kernel/locking/lglock.c
+++ b/kernel/locking/lglock.c
@@ -60,6 +60,28 @@ void lg_local_unlock_cpu(struct lglock *lg, int cpu)
}
EXPORT_SYMBOL(lg_local_unlock_cpu);
+void lg_double_lock(struct lglock *lg, int cpu1, int cpu2)
+{
+ BUG_ON(cpu1 == cpu2);
+
+ /* lock in cpu order, just like lg_global_lock */
+ if (cpu2 < cpu1)
+ swap(cpu1, cpu2);
+
+ preempt_disable();
+ lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+ arch_spin_lock(per_cpu_ptr(lg->lock, cpu1));
+ arch_spin_lock(per_cpu_ptr(lg->lock, cpu2));
+}
+
+void lg_double_unlock(struct lglock *lg, int cpu1, int cpu2)
+{
+ lock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ arch_spin_unlock(per_cpu_ptr(lg->lock, cpu1));
+ arch_spin_unlock(per_cpu_ptr(lg->lock, cpu2));
+ preempt_enable();
+}
+
void lg_global_lock(struct lglock *lg)
{
int i;