在用 perf 分析具有用户空间和内核空间代码的应用程序时，启用各种内核配置的所有其他可能性，但无法单独获得用户空间/内核空间中的指令/周期数。

于是尝试使用 ":u" 和 ":k" 扩展指令和周期计数，但我得到的结果是：

$ perf stat -e cycles:u,instructions:u ls

 Performance counter stats for 'ls':

   <not supported>      cycles:u

   <not supported>      instructions:u

       0.006047045 seconds time elapsed

       0.000000000 seconds user
       0.008098000 seconds sys

但是，仅针对循环/指令运行又给出如下所示的正确结果。

$ perf stat -e cycles,instructions ls

 Performance counter stats for 'ls':

          5362086      cycles
            528783      instructions              #    0.10  insn per cycle

       0.005487940 seconds time elapsed

       0.007800000 seconds user
       0.000000000 seconds sys

ps：

1，ls 在这里只是作为一个例子来突出这个问题。

2，运行的是 Linux 5.4 和 perf 版本 5.4.77.g1206eede9156，而且在 ARM 板上运行上述命令。

下面是在 Linux 内核中启用的配置：

CONFIG_PERF_EVENTS=y
CONFIG_PROFILING=y
CONFIG_TRACEPOINTS=y
CONFIG_KPROBES=y
CONFIG_OPTPROBES=y
CONFIG_KPROBES_ON_FTRACE=y
CONFIG_UPROBES=y
CONFIG_HAVE_KPROBES=y
CONFIG_HAVE_KRETPROBES=y
CONFIG_HAVE_OPTPROBES=y
CONFIG_HAVE_KPROBES_ON_FTRACE=y
CONFIG_DEBUG_INFO=y
CONFIG_DEBUG_INFO_DWARF4=y
CONFIG_FRAME_POINTER=y
CONFIG_FTRACE=y
CONFIG_KPROBE_EVENTS=y
CONFIG_UPROBE_EVENTS=y
CONFIG_PROBE_EVENTS=y

此外，命令行上的 perf list 列出了硬件/软件事件等等

$ perf list
  branch-instructions OR branches                    [Hardware event]
  branch-misses                                      [Hardware event]
  cache-misses                                       [Hardware event]
  cache-references                                   [Hardware event]
  cpu-cycles OR cycles                               [Hardware event]
  instructions                                       [Hardware event]
  alignment-faults                                   [Software event]
  bpf-output                                         [Software event]
  context-switches OR cs                             [Software event]
  cpu-clock                                          [Software event]
  cpu-migrations OR migrations                       [Software event]
  dummy                                              [Software event]
  emulation-faults                                   [Software event]
  major-faults                                       [Software event]
  minor-faults                                       [Software event]
  page-faults OR faults                              [Software event]
  task-clock                                         [Software event]
  duration_time                                      [Tool event]
  L1-dcache-load-misses                              [Hardware cache event]
  L1-dcache-loads                                    [Hardware cache event]
  L1-dcache-prefetch-misses                          [Hardware cache event]
  L1-dcache-prefetches                               [Hardware cache event]
  L1-dcache-store-misses                             [Hardware cache event]
  L1-dcache-stores                                   [Hardware cache event]
  L1-icache-load-misses                              [Hardware cache event]
  L1-icache-loads                                    [Hardware cache event]
  L1-icache-prefetch-misses                          [Hardware cache event]
  L1-icache-prefetches                               [Hardware cache event]
  branch-load-misses                                 [Hardware cache event]
  branch-loads                                       [Hardware cache event]
  dTLB-load-misses                                   [Hardware cache event]
  dTLB-store-misses                                  [Hardware cache event]
  iTLB-load-misses                                   [Hardware cache event]

那应该如何解决此问题？是我哪里做错了什么吗？