PEBS not supported even if CPU microcode is updated to 0x28?

u***@kristnet.org

2012-09-18 06:40:33 UTC

Hi,

Perf does not seem to be able to handle PEBS, even with the new CPU
0x28 microcode.

Post by u***@kristnet.org
sudo ./perf stat -e branches:pp "true"

Performance counter stats for 'true':

<not supported> branches:pp

0.000717042 seconds time elapsed

The output from dmsg write "PEBS is disabled due to CPU errata" BEFORE
the microcode is updated during the boot processs later. I guess that
may be the problem?

What can I try more to get support for PEBS?

Thanks.

/Ulrik

...
[ 0.003839] ACPI: Core revision 20120320
[ 0.012024] ftrace: allocating 23614 entries in 93 pages
[ 0.020716] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
[ 0.120589] CPU0: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz stepping
07
[ 0.237328] Performance Events: PEBS fmt1+, 16-deep LBR, SandyBridge
events, Intel PMU driver.
[ 0.237332] PEBS disabled due to CPU errata.
[ 0.237333] ... version: 3
[ 0.237334] ... bit width: 48
[ 0.237334] ... generic registers: 4
[ 0.237335] ... value mask: 0000ffffffffffff
[ 0.237336] ... max period: 000000007fffffff
[ 0.237336] ... fixed-purpose events: 3
[ 0.237337] ... event mask: 000000070000000f
[ 0.237434] Booting Node 0, Processors #1 #2 #3 #4 #5 #6 #7 Ok.
[ 0.329982] Brought up 8 CPUs
...
[ 15.144230] microcode: CPU0 updated to revision 0x28, date =
2012-04-24
[ 15.144554] microcode: CPU1 updated to revision 0x28, date =
2012-04-24
[ 15.144897] microcode: CPU2 updated to revision 0x28, date =
2012-04-24
[ 15.145245] microcode: CPU3 updated to revision 0x28, date =
2012-04-24
[ 15.145573] microcode: CPU4 updated to revision 0x28, date =
2012-04-24
[ 15.145923] microcode: CPU5 updated to revision 0x28, date =
2012-04-24
[ 15.146269] microcode: CPU6 updated to revision 0x28, date =
2012-04-24
[ 15.146615] microcode: CPU7 updated to revision 0x28, date =
2012-04-24

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 42
model name : Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
stepping : 7
microcode : 0x28
cpu MHz : 1600.000
cache size : 8192 KB
physical id : 0
siblings : 8
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl
xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx
smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt
tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts
dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips : 7004.38
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

I'm running Kernel 3.5.4 with the patch
https://patchwork.kernel.org/patch/1329691/