Currently perf has a feature to account cycles for LBRs
For example, on skylake,
perf record -b ...
perf report or
perf annotate
And then browsing the annotate browser gives average cycle counts
for program blocks.
For some analysis it would be useful if we could know not only
the average cycles but also the max and min cycles.
Now, for example, when press 'c', the annotate view is:
Percent│ IPC Cycle(max/min)
│
│
│ Disassembly of section .text:
│
│ 000000000003aab0 <random@@GLIBC_2.2.5>:
8.22 │3.92 sub $0x18,%rsp
│3.92 mov $0x1,%esi
│3.92 xor %eax,%eax
│3.92 cmpl $0x0,argp_program_version_hook@@G
│3.92 1(2/1) ↓ je 20
│ lock cmpxchg %esi,__abort_msg@@GLIBC_P
│ ↓ jne 29
│ ↓ jmp 43
│1.10 20: cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+
8.93 │1.10 1(5/1) ↓ je 43
When press 'c' again, the annotate view is switched back:
Percent│ IPC Cycle
│
│
│ Disassembly of section .text:
│
│ 000000000003aab0 <random@@GLIBC_2.2.5>:
8.22 │3.92 sub $0x18,%rsp
│3.92 mov $0x1,%esi
│3.92 xor %eax,%eax
│3.92 cmpl $0x0,argp_program_version_hook@@GLIBC_2.2.5+0x
│3.92 1 ↓ je 20
│ lock cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+0x8a0
│ ↓ jne 29
│ ↓ jmp 43
│1.10 20: cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+0x8a0
8.93 │1.10 1 ↓ je 43
Jin Yao (2):
perf annotate: Record the max/min cycles
perf annotate: Create hotkey 'c' to show max/min cycles
tools/perf/ui/browsers/annotate.c | 8 ++++++
tools/perf/util/annotate.c | 51 +++++++++++++++++++++++++++++++++------
tools/perf/util/annotate.h | 11 ++++++++-
3 files changed, 62 insertions(+), 8 deletions(-)
--
2.7.4
