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-rw-r--r--tools/perf/builtin-record.c22
1 files changed, 3 insertions, 19 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d7886307f6f4..caf927978d92 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -115,27 +115,11 @@ static void mmap_read(struct perf_mmap *md)
115 unsigned char *data = md->base + page_size; 115 unsigned char *data = md->base + page_size;
116 unsigned long size; 116 unsigned long size;
117 void *buf; 117 void *buf;
118 int diff;
119 118
120 /* 119 if (old == head)
121 * If we're further behind than half the buffer, there's a chance 120 return;
122 * the writer will bite our tail and mess up the samples under us.
123 *
124 * If we somehow ended up ahead of the head, we got messed up.
125 *
126 * In either case, truncate and restart at head.
127 */
128 diff = head - old;
129 if (diff < 0) {
130 fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
131 /*
132 * head points to a known good entry, start there.
133 */
134 old = head;
135 }
136 121
137 if (old != head) 122 samples++;
138 samples++;
139 123
140 size = head - old; 124 size = head - old;
141 125