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| author | Thomas Richter <tmricht@linux.ibm.com> | 2018-04-12 15:32:46 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-04-13 09:59:56 -0300 |
| commit | 4f75f1cbf95e2f0853cd229d042b203931b899af (patch) | |
| tree | 4c0fbd52584ffe69b3a96e253599b3b3b0d971b9 /tools | |
| parent | 4b163ca343b45855b03114ef2ab47c454989d55c (diff) | |
| download | linux-stable-4f75f1cbf95e2f0853cd229d042b203931b899af.tar.gz linux-stable-4f75f1cbf95e2f0853cd229d042b203931b899af.tar.bz2 linux-stable-4f75f1cbf95e2f0853cd229d042b203931b899af.zip | |
perf record: Change warning for missing sysfs entry to debug
Using perf on 4.16.0 kernel on s390 shows this warning:
failed: can't open node sysfs data
each time I run command perf record ... for example:
[root@s35lp76 perf]# ./perf record -e rB0000 -- sleep 1
[ perf record: Woken up 1 times to write data ]
failed: can't open node sysfs data
[ perf record: Captured and wrote 0.001 MB perf.data (4 samples) ]
[root@s35lp76 perf]#
It turns out commit e2091cedd51bf ("perf tools: Add MEM_TOPOLOGY feature
to perf data file") tries to open directory named /sys/devices/system/node/
which does not exist on s390.
This is the call stack:
__cmd_record
+---> perf_session__write_header
+---> perf_header__adds_write
+---> do_write_feat
+---> write_mem_topology
+---> build_mem_topology
prints warning
The issue starts in do_write_feat() which unconditionally loops over all
features and now includes HEADER_MEM_TOPOLOGY and calls write_mem_topology().
Function record__init_features() at the beginning of __cmd_record() sets
all features and then turns off some of them.
Fix this by changing the warning to a level 2 debug output statement.
So it is only shown when debug level 2 or higher is set.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180412133246.92801-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/header.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 121df1683c36..a8bff2178fbc 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1320,7 +1320,8 @@ static int build_mem_topology(struct memory_node *nodes, u64 size, u64 *cntp) dir = opendir(path); if (!dir) { - pr_warning("failed: can't open node sysfs data\n"); + pr_debug2("%s: could't read %s, does this arch have topology information?\n", + __func__, path); return -1; } |