From: Franck Bui-Huu <fbuihuu@gmail.com>
Date: Tue, 30 Nov 2010 11:50:14 +0000 (+0100)
Subject: perf header: Don't assume there's no attr info if no sample ids is provided
X-Git-Tag: v2.6.37-rc6~36^3~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=60e677373be9c0bf7c9a22937601d5a40e51c042;p=profile%2Fivi%2Fkernel-x86-ivi.git

perf header: Don't assume there's no attr info if no sample ids is provided

This primarily fixes perf-report, which didn't report the correct type
of event if perf-record was called to record one event different from
'cycles':

  $ perf record -e instructions true
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.007 MB perf.data (~295 samples) ]

  $ perf report | head -n1
    # Events: 7  cycles

LPU-Reference: <m3mxor6nex.fsf@gmail.com>
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
---

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index d7e67b1..64a85ba 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -946,11 +946,16 @@ perf_header__find_attr(u64 id, struct perf_header *header)
 
 	/*
 	 * We set id to -1 if the data file doesn't contain sample
-	 * ids. Check for this and avoid walking through the entire
-	 * list of ids which may be large.
+	 * ids. This can happen when the data file contains one type
+	 * of event and in that case, the header can still store the
+	 * event attribute information. Check for this and avoid
+	 * walking through the entire list of ids which may be large.
 	 */
-	if (id == -1ULL)
+	if (id == -1ULL) {
+		if (header->attrs > 0)
+			return &header->attr[0]->attr;
 		return NULL;
+	}
 
 	for (i = 0; i < header->attrs; i++) {
 		struct perf_header_attr *attr = header->attr[i];