Messages in this thread Patch in this message | | | Date | Thu, 19 Nov 2015 14:13:53 -0800 | From | Sukadev Bhattiprolu <> | Subject | perf test topo broken? |
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'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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