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Subjectperf test topo broken?

'perf test topo' is broken on my x86_64 system, with a rather cryptic message.

$ ./perf test -v topo
36: Test topology in session :
--- start ---
test child forked, pid 2705
templ file: /tmp/perf-test-6rSAkb
core_id number is too big. nr 9, cpu_nr 8. You may need to upgrade the perf tool.
test child interrupted
---- end ----
Test topology in session: FAILED!

$ ./perf --version
perf version 4.4.rc1.g34258a

(I included nr and cpu_nr values in the error message). The code (shown
below) is comparing a core_id value (nr) with number of cpus online (cpu_nr)
which don't seem to be related on this system.

On my system running 4.4.0-rc1 kernel, I have following cpus:

$ head /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 44
model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz
stepping : 2
microcode : 0x10
cpu MHz : 1596.000
cache size : 12288 KB
physical id : 0

$ ls -d /sys/devices/system/cpu/cpu?
/sys/devices/system/cpu/cpu0 /sys/devices/system/cpu/cpu4
/sys/devices/system/cpu/cpu1 /sys/devices/system/cpu/cpu5
/sys/devices/system/cpu/cpu2 /sys/devices/system/cpu/cpu6
/sys/devices/system/cpu/cpu3 /sys/devices/system/cpu/cpu7

$ cat /sys/devices/system/cpu/online
0-7

$ cat /sys/devices/system/cpu/cpu?/topology/core_id
0
1
9
10
0
1
9
10

Commenting out following code seems to cause the test to pass, but are
core_ids in general related to number of cpus online?

Sukadev

---
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 4383800..d5104da 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1652,11 +1652,14 @@ static int process_cpu_topology(struct perf_file_section *section,
if (ph->needs_swap)
nr = bswap_32(nr);

+#if 0
if (nr > (u32)cpu_nr) {
- pr_debug("core_id number is too big."
- "You may need to upgrade the perf tool.\n");
+ pr_debug("core_id number is too big. nr %d, cpu_nr %d. "
+ "You may need to upgrade the perf tool.\n",
+ nr, cpu_nr);
goto free_cpu;
}
+#endif
ph->env.cpu[i].core_id = nr;

ret = readn(fd, &nr, sizeof(nr));


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