Messages in this thread | | | Date | Thu, 11 Mar 2010 19:16:46 +0100 | From | Ingo Molnar <> | Subject | Re: [RFC] x86,perf: Implement minimal P4 PMU driver v14 |
| |
* Cyrill Gorcunov <gorcunov@openvz.org> wrote:
> x86,perf: Implement minimal P4 PMU driver v15
tried it on a Pentium-D dual core CPU, and it boots fine:
[ 0.020009] using mwait in idle threads. [ 0.021004] Performance Events: Netburst events, Netburst P4/Xeon PMU driver. [ 0.024006] ... version: 0 [ 0.025003] ... bit width: 40 [ 0.026003] ... generic registers: 18 [ 0.027003] ... value mask: 000000ffffffffff [ 0.028003] ... max period: 0000007fffffffff [ 0.029003] ... fixed-purpose events: 0 [ 0.030003] ... event mask: 000000000003ffff [ 0.031027] ACPI: Core revision 20100121 [ 0.050126] Setting APIC routing to flat [ 0.051010] enabled ExtINT on CPU#0
perf stat seems to work fine as well:
rhea:~> perf stat ls >/dev/null
Performance counter stats for 'ls':
6.596037 task-clock-msecs # 0.439 CPUs 1 context-switches # 0.000 M/sec 0 CPU-migrations # 0.000 M/sec 236 page-faults # 0.036 M/sec 4745843 cycles # 719.499 M/sec 0 instructions # 0.000 IPC <not counted> cache-references <not counted> cache-misses
0.015009286 seconds time elapsed
perf top works fine as well:
------------------------------------------------------------------------------ PerfTop: 25056 irqs/sec kernel:25.7% [100000 cycles], (all, 2 CPUs) ------------------------------------------------------------------------------
samples pcnt kernel function _______ _____ _______________
845.00 - 6.6% : __switch_to 785.00 - 6.1% : schedule 687.00 - 5.3% : perf_poll 455.00 - 3.5% : _raw_spin_lock_irqsave 436.00 - 3.4% : delay_tsc 371.00 - 2.9% : fget_light 346.00 - 2.7% : pick_next_task_fair 328.00 - 2.5% : fput 285.00 - 2.2% : free_poll_entry
i also triggered this:
[ 436.224139] PMU: Dep events are not implemented yet
i'm getting a healthy amount of NMIs:
NMI: 44400 108796 Non-maskable interrupts
perf record + report works fine too:
# Samples: 32829281626 # # Overhead Command Shared Object Symbol # ........ ............... .................. ...... # 11.22% pipe-test-1m [kernel.kallsyms] [k] __switch_to 4.82% pipe-test-1m [kernel.kallsyms] [k] switch_mm 4.37% pipe-test-1m [kernel.kallsyms] [k] schedule 3.01% pipe-test-1m [kernel.kallsyms] [k] pipe_read 2.96% pipe-test-1m [kernel.kallsyms] [k] system_call 2.53% pipe-test-1m [kernel.kallsyms] [k] update_curr 2.15% pipe-test-1m [kernel.kallsyms] [k] vfs_read
perf annotate __switch_to works too, and sees inside irqs-disabled regions due to NMI sampling:
0.00 : ffffffff81001664: 48 89 c2 mov %rax,%rdx 0.18 : ffffffff81001667: b9 00 01 00 c0 mov $0xc0000100,%ecx 0.00 : ffffffff8100166c: 48 c1 ea 20 shr $0x20,%rdx 0.00 : ffffffff81001670: 0f 30 wrmsr 67.80 : ffffffff81001672: 45 85 ff test %r15d,%r15d 1.85 : ffffffff81001675: 66 89 b3 8c 04 00 00 mov %si,0x48c(%rbx) 5.35 : ffffffff8100167c: 41 0f b7 bd 8e 04 00 movzwl 0x48e(%r13),%edi 0.00 : ffffffff81001683: 00
(and that wrmsr is indeed one known overhead point in __switch_to.)
All in one, the P4 PMU perf driver works on this box like a charm and all the common profiling workflows work out of box, without any serious limitations - really nice work! (Obviously some events wont work yet, etc.)
So it's pretty impressive and i've queued up your patch in tip:perf/x86 and will merge it into perf/core after others had a chance to test it too.
Ingo
| |