Re: [tip:perf/core] perf/x86/intel/P4: Robistify P4 PMU types

From: Borislav Petkov
Date: Sat Apr 27 2013 - 12:14:19 EST


On Fri, Apr 26, 2013 at 08:46:52PM +0400, Cyrill Gorcunov wrote:
> On Fri, Apr 26, 2013 at 06:39:52PM +0200, Borislav Petkov wrote:
> > # 0.25 stalled cycles per insn
> > 590,855 branches # 237.877 M/sec
> > 12,882 branch-misses # 2.18% of all branches
> > ^^^^^^^^^^^^^^^^^^^^
> >
> > Those above?

Well, perf top looks ok to me, here's a snapshot:

PerfTop: 63 irqs/sec kernel:79.4% exact: 0.0% [4000Hz cycles], (all, 2 CPUs)
--------------------------------------------------------------------------------------------------------------------------------------------

11.21% [kernel] [k] __lock_acquire
7.87% libc-2.13.so [.] 0x00078b0c
5.78% libz.so.1.2.7 [.] 0x00003731
4.29% libpthread-2.13.so [.] pthread_rwlock_unlock
3.74% libpthread-2.13.so [.] pthread_rwlock_rdlock
3.67% [kernel] [k] lock_release
2.55% [kernel] [k] lock_acquire
2.27% perf [.] symbols__insert
2.15% sshd [.] 0x0004707e
1.62% libc-2.13.so [.] vfprintf
1.58% [kernel] [k] mark_held_locks
1.40% [kernel] [k] do_raw_spin_lock
1.37% [kernel] [k] trace_hardirqs_on_caller
1.29% [kernel] [k] sub_preempt_count
1.17% perf [.] symbol_filter
1.13% [kernel] [k] mark_lock
1.05% [kernel] [k] trace_hardirqs_off_caller
0.96% perf [.] rb_next
0.94% libc-2.13.so [.] memchr
0.80% libbfd-2.22-system.so [.] 0x000bb009
0.72% [kernel] [k] __schedule
0.71% [kernel] [k] ioread16
0.67% [kernel] [k] _raw_spin_unlock_irqrestore
0.66% [kernel] [k] __switch_to
0.59% [kernel] [k] do_raw_spin_unlock
0.56% perf [.] dso__load_sym
...

I can annotate symbols and disassemble works fine too, along with
refresh and per-insn overhead.

The other trivial test passes too, although branch-misses doesn't get
counted:

./perf stat sleep 1

Performance counter stats for 'sleep 1':

1.433368 task-clock # 0.001 CPUs utilized
1 context-switches # 0.698 K/sec
0 cpu-migrations # 0.000 K/sec
147 page-faults # 0.103 M/sec
78,446 cycles # 0.055 GHz
0 stalled-cycles-frontend # 0.00% frontend cycles idle
0 stalled-cycles-backend # 0.00% backend cycles idle [27.37%]
1,268,044 instructions # 16.16 insns per cycle [27.37%]
223,742 branches # 156.095 M/sec [27.37%]
<not counted> branch-misses

1.002191045 seconds time elapsed

However, if I do this, it works:

./perf stat -e branch-misses sleep 1

Performance counter stats for 'sleep 1':

8,583 branch-misses

1.001992384 seconds time elapsed


Oh, btw, tip/master has

commit 697dfd884438058b15032b0169887c742704434a
Merge: 0fbd06761f5c f697036b93aa
Author: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Date: Thu Apr 25 14:00:22 2013 -0700

Merge tag 'efi-urgent' into x86/urgent

as its top commit.

HTH.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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