mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-13 06:08:07 +00:00
6920e2854e
So at the top we'll have two lines, like this, from 'perf report':
# perf report --group --ignore-vmlinux
=====================================================================================================
Samples: 46 of events 'cycles', 4000 Hz, Event count (approx.): 5154895
_raw_spin_lock_irqsave /proc/kcore
Percent │ nop
│ push %rbx
0.00 14.29 0.00 │ pushfq
9.09 0.00 0.00 │ pop %rax
9.09 0.00 20.00 │ nop
│ mov %rax,%rbx
│ cli
4.55 7.14 0.00 │ nop
│ xor %eax,%eax
│ mov $0x1,%edx
│ lock cmpxchg %edx,(%rdi)
77.27 78.57 70.00 │ test %eax,%eax
│ ↓ jne 2b
│ mov %rbx,%rax
0.00 0.00 10.00 │ pop %rbx
│ ← retq
│2b: mov %eax,%esi
│ → callq queued_spin_lock_slowpath
│ mov %rbx,%rax
│ pop %rbx
Press 'h' for help on│key bindings
=====================================================================================================
9.09 + 9.09 + 4.55 + 77.27 = 100
14.29 + 7.14 + 78.57 = 100
20 + 70 + 10 = 100
We can do the math by using 't' to toggle from 'percent' to nr
=====================================================================================================
Samples: 46 of events 'cycles', 4000 Hz, Event count (approx.): 5154895
_raw_spin_lock_irqsave /proc/kcore
Period │ nop
│ push %rbx
0 79273 0 │ pushfq
190455 0 0 │ pop %rax
198038 0 3045 │ nop
│ mov %rax,%rbx
│ cli
217233 32562 0 │ nop
│ xor %eax,%eax
│ mov $0x1,%edx
│ lock cmpxchg %edx,(%rdi)
3421649 979174 28273 │ test %eax,%eax
│ ↓ jne 2b
│ mov %rbx,%rax
0 0 5193 │ pop %rbx
│ ← retq
│2b: mov %eax,%esi
│ → callq queued_spin_lock_slowpath
│ mov %rbx,%rax
│ pop %rbx
Press 'h' for help on│key bindings
=====================================================================================================
79273 + 190455 + 198038 + 3045 + 217233 + 32562 + 3421649 + 979174 + 28273 + 5193 = 5154895
Or number of samples:
=====================================================================================================
ooSamples: 46 of events 'cycles', 4000 Hz, Event count (approx.): 5154895
_raw_spin_lock_irqsave /proc/kcore
Samples │ nop
│ push %rbx
0 2 0 │ pushfq
2 0 0 │ pop %rax
2 0 2 │ nop
│ mov %rax,%rbx
│ cli
1 1 0 │ nop
│ xor %eax,%eax
│ mov $0x1,%edx
│ lock cmpxchg %edx,(%rdi)
17 11 7 │ test %eax,%eax
│ ↓ jne 2b
│ mov %rbx,%rax
0 0 1 │ pop %rbx
│ ← retq
│2b: mov %eax,%esi
│ → callq queued_spin_lock_slowpath
│ mov %rbx,%rax
│ pop %rbx
Press 'h' for help on key bindings
=====================================================================================================
2 + 2 + 2 + 2 + 1 + 1 + 17 + 11 + 7 + 1 = 46
Suggested-by: Martin Liška <mliska@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196935
Link: https://lkml.kernel.org/n/tip-ezccyxld50wtwyt66np6aomo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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|---|---|---|
| .. | ||
| arch | ||
| bench | ||
| Documentation | ||
| jvmti | ||
| pmu-events | ||
| python | ||
| scripts | ||
| tests | ||
| trace | ||
| ui | ||
| util | ||
| .gitignore | ||
| Build | ||
| builtin-annotate.c | ||
| builtin-bench.c | ||
| builtin-buildid-cache.c | ||
| builtin-buildid-list.c | ||
| builtin-c2c.c | ||
| builtin-config.c | ||
| builtin-data.c | ||
| builtin-diff.c | ||
| builtin-evlist.c | ||
| builtin-ftrace.c | ||
| builtin-help.c | ||
| builtin-inject.c | ||
| builtin-kallsyms.c | ||
| builtin-kmem.c | ||
| builtin-kvm.c | ||
| builtin-list.c | ||
| builtin-lock.c | ||
| builtin-mem.c | ||
| builtin-probe.c | ||
| builtin-record.c | ||
| builtin-report.c | ||
| builtin-sched.c | ||
| builtin-script.c | ||
| builtin-stat.c | ||
| builtin-timechart.c | ||
| builtin-top.c | ||
| builtin-trace.c | ||
| builtin-version.c | ||
| builtin.h | ||
| check-headers.sh | ||
| command-list.txt | ||
| CREDITS | ||
| design.txt | ||
| Makefile | ||
| Makefile.config | ||
| Makefile.perf | ||
| MANIFEST | ||
| perf-archive.sh | ||
| perf-completion.sh | ||
| perf-read-vdso.c | ||
| perf-sys.h | ||
| perf-with-kcore.sh | ||
| perf.c | ||
| perf.h | ||