Messages in this thread | | | Date | Wed, 28 Nov 2018 10:10:05 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH v3 0/3] perf report/annotate: Support average IPC and IPC coverage for function |
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* Jin Yao <yao.jin@linux.intel.com> wrote:
> Add supporting of displaying the average IPC and IPC coverage > percentage per function. > > For example, > > $ perf record -b ... > $ perf report -s symbol or > perf report -s symbol --stdio > > Overhead Symbol IPC [IPC Coverage] > 39.60% [.] __random 2.30 [ 54.8%] > 18.02% [.] main 0.43 [ 54.3%] > 14.21% [.] compute_flag 2.29 [100.0%] > 14.16% [.] rand 0.36 [100.0%] > 7.06% [.] __random_r 2.57 [ 70.5%] > 6.85% [.] rand@plt 0.00 [ 0.0%] > ... > > $ perf annotate --stdio2 > > Percent IPC Cycle (Average IPC: 2.30, IPC Coverage: 54.8%) > > Disassembly of section .text: > > 000000000003aac0 <random@@GLIBC_2.2.5>: > 8.32 3.28 sub $0x18,%rsp > 3.28 mov $0x1,%esi > 3.28 xor %eax,%eax > 3.28 cmpl $0x0,argp_program_version_hook@@GLIBC_2.2.5+0x1e0 > 11.57 3.28 1 ↓ je 20 > lock cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+0x8a0 > ↓ jne 29 > ↓ jmp 43 > 11.57 1.10 20: cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+0x8a0
That's a nice feature: please add meaningful documentation, accessible via the perf help system preferably, that outlines how the IPC metrics should be interpreted and how they are useful when optimizing programs.
Thanks,
Ingo
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