在我真个malloc的执行过程中共调用了8次的syswrite的系统调用，其中有两次来自于__lib_write, 两次来自于__memmove_avx_unaligned，然后__memmove_avx_unaligned中有两次是来自于funca，有两次是来自于funb，所以在总共的8次调用中，有两次是来自于funcb，有两次来自于funca.
这里并不是一个时间的关系呢；
Samples: 8 of event 'syscalls:sys_enter_write, Event count (approx.): 8
Children Self Command Shared Object Symbol ▒
- 100.00% 100.00% malloc malloc [.] __libc_write ▒
- 25.00% 0xa3437 ▒
__libc_write ▒
- 25.00% 0x860f20f983483fe1 ▒
__memmove_avx_unaligned ▒
generic_start_main ▒
- main ▒
- 12.50% funcb ▒
func1 ▒
func2 ▒
func3 ▒
__libc_write ▒
- 12.50% funca ▒
func1 ▒
func2 ▒
func3 ▒
__libc_write ▒
- 25.00% 0xa3031300a3437 ▒
__libc_write ▒
- 12.50% 0xa303130353532 ▒
__libc_write ▒
- 12.50% 0xa303130343132 ▒
__libc_write ▒
+ 25.00% 0.00% malloc malloc [.] func3 ◆
+ 25.00% 0.00% malloc [unknown] [.] 0x00000000000a3437 ▒
+ 25.00% 0.00% malloc [unknown] [.] 0x000a3031300a3437 ▒
+ 25.00% 0.00% malloc malloc [.] func2 ▒
+ 25.00% 0.00% malloc malloc [.] func1 ▒
+ 25.00% 0.00% malloc malloc [.] main ▒
+ 25.00% 0.00% malloc malloc [.] generic_start_main ▒
+ 25.00% 0.00% malloc malloc [.] __memmove_avx_unaligned ▒
+ 25.00% 0.00% malloc [unknown] [.] 0x860f20f983483fe1 ▒
+ 12.50% 0.00% malloc [unknown] [.] 0x000a303130343132 ▒
+ 12.50% 0.00% malloc [unknown] [.] 0x000a303130353532 ▒
+ 12.50% 0.00% malloc malloc [.] funca ▒
+ 12.50% 0.00% malloc malloc [.] funcb ▒
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为了能够更加精确地看到软件事件的发生，我们选择一个比较生僻的系统调用来观察 perf_event_open