Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul E. McKenney:

- 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().

- Miscellaneous fixes.

- Torture-test updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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;