Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Fixes and improvements for perf/core:

. Overhaul the tools/ makefiles, gluing them to the top level Makefile, from
  Borislav Petkov.

. Move the UI files from tools/perf/util/ui/ to tools/perf/ui/. Also move
  the GTK+ browser to tools/perf/ui/gtk/, from Namhyung Kim.

. Only fallback to sw cycles counter on ENOENT for the hw cycles, from
  Robert Richter

. Trivial fixes from Robert Richter

. Handle the autogenerated bison/flex files better, from Namhyung and Jiri Olsa.

. Navigate jump instructions in the annotate browser, just press enter or ->,
  still needs support for a jump navigation history, i.e. to go back.

. Search string in the annotate browser: same keys as vim:
     / forward
     n next backward/forward
     ? backward

. Clarify number of events/samples in the report header, from Ashay Rane

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 67458468f1a..e8ee5dd0854 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -61,6 +61,24 @@ extern void synchronize_rcu_bh(void);
 extern void synchronize_sched_expedited(void);
 extern void synchronize_rcu_expedited(void);
 
+void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
+
+/**
+ * synchronize_rcu_bh_expedited - Brute-force RCU-bh grace period
+ *
+ * Wait for an RCU-bh grace period to elapse, but use a "big hammer"
+ * approach to force the grace period to end quickly.  This consumes
+ * significant time on all CPUs and is unfriendly to real-time workloads,
+ * so is thus not recommended for any sort of common-case code.  In fact,
+ * if you are using synchronize_rcu_bh_expedited() in a loop, please
+ * restructure your code to batch your updates, and then use a single
+ * synchronize_rcu_bh() instead.
+ *
+ * Note that it is illegal to call this function while holding any lock
+ * that is acquired by a CPU-hotplug notifier.  And yes, it is also illegal
+ * to call this function from a CPU-hotplug notifier.  Failing to observe
+ * these restriction will result in deadlock.
+ */
 static inline void synchronize_rcu_bh_expedited(void)
 {
 	synchronize_sched_expedited();
@@ -83,6 +101,7 @@ extern void rcu_sched_force_quiescent_state(void);
 /* A context switch is a grace period for RCU-sched and RCU-bh. */
 static inline int rcu_blocking_is_gp(void)
 {
+	might_sleep();  /* Check for RCU read-side critical section. */
 	return num_online_cpus() == 1;
 }