Merge tag 'perf-urgent-for-mingo-4.17-20180420' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes and improvements from Arnaldo Carvalho de Melo:

- Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE].
  The percentage of preempting and non-preempting context switches help
  understanding the nature of workloads (CPU or IO bound) that are running
  on a machine. This adds the kernel facility and userspace changes needed
  to show this information in 'perf script' and 'perf report -D' (Alexey Budankov)

- Remove old error messages about things that unlikely to be the root cause
  in modern systems (Andi Kleen)

- Synchronize kernel ABI headers, v4.17-rc1 (Ingo Molnar)

- Support MAP_FIXED_NOREPLACE, noticed when updating the tools/include/
  copies (Arnaldo Carvalho de Melo)

- Fixup BPF test using epoll_pwait syscall function probe, to cope with
  the syscall routines renames performed in this development cycle (Arnaldo Carvalho de Melo)

- Fix sample_max_stack maximum check and do not proceed when an error
  has been detect, return them to avoid misidentifying errors (Jiri Olsa)

- Add '\n' at the end of parse-options error messages (Ravi Bangoria)

- Add s390 support for detailed/verbose PMU event description (Thomas Richter)

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

2 files changed, 17 insertions, 16 deletions

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 772a43fea825..c187aa3df3c8 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -119,23 +119,20 @@ int get_callchain_buffers(int event_max_stack)
 		goto exit;
 	}
 
-	if (count > 1) {
-		/* If the allocation failed, give up */
-		if (!callchain_cpus_entries)
-			err = -ENOMEM;
-		/*
-		 * If requesting per event more than the global cap,
-		 * return a different error to help userspace figure
-		 * this out.
-		 *
-		 * And also do it here so that we have &callchain_mutex held.
-		 */
-		if (event_max_stack > sysctl_perf_event_max_stack)
-			err = -EOVERFLOW;
+	/*
+	 * If requesting per event more than the global cap,
+	 * return a different error to help userspace figure
+	 * this out.
+	 *
+	 * And also do it here so that we have &callchain_mutex held.
+	 */
+	if (event_max_stack > sysctl_perf_event_max_stack) {
+		err = -EOVERFLOW;
 		goto exit;
 	}
 
-	err = alloc_callchain_buffers();
+	if (count == 1)
+		err = alloc_callchain_buffers();
 exit:
 	if (err)
 		atomic_dec(&nr_callchain_events);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 2d5fe26551f8..67612ce359ad 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7587,6 +7587,10 @@ static void perf_event_switch(struct task_struct *task,
 		},
 	};
 
+	if (!sched_in && task->state == TASK_RUNNING)
+		switch_event.event_id.header.misc |=
+				PERF_RECORD_MISC_SWITCH_OUT_PREEMPT;
+
 	perf_iterate_sb(perf_event_switch_output,
 		       &switch_event,
 		       NULL);
@@ -10205,9 +10209,9 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
 		 * __u16 sample size limit.
 		 */
 		if (attr->sample_stack_user >= USHRT_MAX)
-			ret = -EINVAL;
+			return -EINVAL;
 		else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
-			ret = -EINVAL;
+			return -EINVAL;
 	}
 
 	if (!attr->sample_max_stack)