Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "The main RCU changes in this cycle were:

   - Updates to use cond_resched() instead of cond_resched_rcu_qs()
     where feasible (currently everywhere except in kernel/rcu and in
     kernel/torture.c). Also a couple of fixes to avoid sending IPIs to
     offline CPUs.

   - Updates to simplify RCU's dyntick-idle handling.

   - Updates to remove almost all uses of smp_read_barrier_depends() and
     read_barrier_depends().

   - Torture-test updates.

   - Miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  torture: Save a line in stutter_wait(): while -> for
  torture: Eliminate torture_runnable and perf_runnable
  torture: Make stutter less vulnerable to compilers and races
  locking/locktorture: Fix num reader/writer corner cases
  locking/locktorture: Fix rwsem reader_delay
  torture: Place all torture-test modules in one MAINTAINERS group
  rcutorture/kvm-build.sh: Skip build directory check
  rcutorture: Simplify functions.sh include path
  rcutorture: Simplify logging
  rcutorture/kvm-recheck-*: Improve result directory readability check
  rcutorture/kvm.sh: Support execution from any directory
  rcutorture/kvm.sh: Use consistent help text for --qemu-args
  rcutorture/kvm.sh: Remove unused variable, `alldone`
  rcutorture: Remove unused script, config2frag.sh
  rcutorture/configinit: Fix build directory error message
  rcutorture: Preempt RCU-preempt readers more vigorously
  torture: Reduce #ifdefs for preempt_schedule()
  rcu: Remove have_rcu_nocb_mask from tree_plugin.h
  rcu: Add comment giving debug strategy for double call_rcu()
  tracing, rcu: Hide trace event rcu_nocb_wake when not used
  ...

2 files changed, 2 insertions, 9 deletions

diff --git a/mm/ksm.c b/mm/ksm.c
index be8f4576f842..c406f75957ad 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -675,15 +675,8 @@ static struct page *get_ksm_page(struct stable_node *stable_node, bool lock_it)
 	expected_mapping = (void *)((unsigned long)stable_node |
 					PAGE_MAPPING_KSM);
 again:
-	kpfn = READ_ONCE(stable_node->kpfn);
+	kpfn = READ_ONCE(stable_node->kpfn); /* Address dependency. */
 	page = pfn_to_page(kpfn);
-
-	/*
-	 * page is computed from kpfn, so on most architectures reading
-	 * page->mapping is naturally ordered after reading node->kpfn,
-	 * but on Alpha we need to be more careful.
-	 */
-	smp_read_barrier_depends();
 	if (READ_ONCE(page->mapping) != expected_mapping)
 		goto stale;
 
diff --git a/mm/mlock.c b/mm/mlock.c
index 30472d438794..f7f54fd2e13f 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -779,7 +779,7 @@ static int apply_mlockall_flags(int flags)
 
 		/* Ignore errors */
 		mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags);
-		cond_resched_rcu_qs();
+		cond_resched();
 	}
 out:
 	return 0;