From 0e8615e359eaa1be4371127e0a96dada1f23248d Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Tue, 6 Jan 2009 13:57:11 +0200
Subject: [PATCH] --- yaml --- r: 140619 b: refs/heads/master c:
 173ed24ee2d64f5de28654eb456ec1ee18a142e5 h: refs/heads/master i:   140617:
 3d047d28115ff7e2305497ef9885e9dfad426ad2   140615:
 f8f1a0d862dd87e4d0dea983b5877d60c9a6451a v: v3

---
 [refs]                               |  2 +-
 trunk/kernel/trace/trace_mmiotrace.c | 14 ++++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 2609b707eb9e..d77afb03943f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: fe6f90e57fd31af8daca534ea01db2e5666c15da
+refs/heads/master: 173ed24ee2d64f5de28654eb456ec1ee18a142e5
diff --git a/trunk/kernel/trace/trace_mmiotrace.c b/trunk/kernel/trace/trace_mmiotrace.c
index fcec59ff2355..621c8c3f3139 100644
--- a/trunk/kernel/trace/trace_mmiotrace.c
+++ b/trunk/kernel/trace/trace_mmiotrace.c
@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/mmiotrace.h>
 #include <linux/pci.h>
+#include <asm/atomic.h>
 
 #include "trace.h"
 #include "trace_output.h"
@@ -20,6 +21,7 @@ struct header_iter {
 static struct trace_array *mmio_trace_array;
 static bool overrun_detected;
 static unsigned long prev_overruns;
+static atomic_t dropped_count;
 
 static void mmio_reset_data(struct trace_array *tr)
 {
@@ -122,11 +124,11 @@ static void mmio_close(struct trace_iterator *iter)
 
 static unsigned long count_overruns(struct trace_iterator *iter)
 {
-	unsigned long cnt = 0;
+	unsigned long cnt = atomic_xchg(&dropped_count, 0);
 	unsigned long over = ring_buffer_overruns(iter->tr->buffer);
 
 	if (over > prev_overruns)
-		cnt = over - prev_overruns;
+		cnt += over - prev_overruns;
 	prev_overruns = over;
 	return cnt;
 }
@@ -308,8 +310,10 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
 
 	event	= ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
 					   &irq_flags);
-	if (!event)
+	if (!event) {
+		atomic_inc(&dropped_count);
 		return;
+	}
 	entry	= ring_buffer_event_data(event);
 	tracing_generic_entry_update(&entry->ent, 0, preempt_count());
 	entry->ent.type			= TRACE_MMIO_RW;
@@ -336,8 +340,10 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
 
 	event	= ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
 					   &irq_flags);
-	if (!event)
+	if (!event) {
+		atomic_inc(&dropped_count);
 		return;
+	}
 	entry	= ring_buffer_event_data(event);
 	tracing_generic_entry_update(&entry->ent, 0, preempt_count());
 	entry->ent.type			= TRACE_MMIO_MAP;