[PATCH v5 3/3] perf script: extend misc field decoding with switch out event type

[Alexey Budankov]

Append 'p' sign to 'S' tag designating the type of context switch out event so 
'Sp' means preemption context switch. Documentation is extended to cover 
new presentation changes.

perf script --show-switch-events -F +misc -I -i perf.data:

          hdparm  4073 [004] U       762.198265:     380194 cycles:ppp:      
7faf727f5a23 strchr (/usr/lib64/ld-2.26.so)
          hdparm  4073 [004] K       762.198366:     441572 cycles:ppp:  
ffffffffb9218435 alloc_set_pte (/lib/modules/4.16.0-rc6+/build/vmlinux)
          hdparm  4073 [004] S       762.198391: PERF_RECORD_SWITCH_CPU_WIDE 
OUT          next pid/tid:     0/0    
         swapper     0 [004]         762.198392: PERF_RECORD_SWITCH_CPU_WIDE IN 
          prev pid/tid:  4073/4073 
         swapper     0 [004] Sp      762.198477: PERF_RECORD_SWITCH_CPU_WIDE 
OUT preempt  next pid/tid:  4073/4073 
          hdparm  4073 [004]         762.198478: PERF_RECORD_SWITCH_CPU_WIDE IN 
          prev pid/tid:     0/0    
         swapper     0 [007] K       762.198514:    2303073 cycles:ppp:  
ffffffffb98b0c66 intel_idle (/lib/modules/4.16.0-rc6+/build/vmlinux)
         swapper     0 [007] Sp      762.198561: PERF_RECORD_SWITCH_CPU_WIDE 
OUT preempt  next pid/tid:  1134/1134 
  kworker/u16:18  1134 [007]         762.198562: PERF_RECORD_SWITCH_CPU_WIDE IN 
          prev pid/tid:     0/0    
  kworker/u16:18  1134 [007] S       762.198567: PERF_RECORD_SWITCH_CPU_WIDE 
OUT          next pid/tid:     0/0    

Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
---
 tools/perf/Documentation/perf-script.txt | 17 +++++++++--------
 tools/perf/builtin-script.c              |  5 ++++-
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/tools/perf/Documentation/perf-script.txt 
b/tools/perf/Documentation/perf-script.txt
index 36ec0257f8d3..afdafe2110a1 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -228,14 +228,15 @@ OPTIONS
        For sample events it's possible to display misc field with -F +misc 
option,
        following letters are displayed for each bit:
 
-         PERF_RECORD_MISC_KERNEL        K
-         PERF_RECORD_MISC_USER          U
-         PERF_RECORD_MISC_HYPERVISOR    H
-         PERF_RECORD_MISC_GUEST_KERNEL  G
-         PERF_RECORD_MISC_GUEST_USER    g
-         PERF_RECORD_MISC_MMAP_DATA*    M
-         PERF_RECORD_MISC_COMM_EXEC     E
-         PERF_RECORD_MISC_SWITCH_OUT    S
+         PERF_RECORD_MISC_KERNEL               K
+         PERF_RECORD_MISC_USER                 U
+         PERF_RECORD_MISC_HYPERVISOR           H
+         PERF_RECORD_MISC_GUEST_KERNEL         G
+         PERF_RECORD_MISC_GUEST_USER           g
+         PERF_RECORD_MISC_MMAP_DATA*           M
+         PERF_RECORD_MISC_COMM_EXEC            E
+         PERF_RECORD_MISC_SWITCH_OUT           S
+         PERF_RECORD_MISC_SWITCH_OUT_PREEMPT   Sp
 
          $ perf script -F +misc ...
           sched-messaging  1414 K     28690.636582:       4590 cycles ...
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 313c42423393..0f916e8e1835 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -657,8 +657,11 @@ static int perf_sample__fprintf_start(struct perf_sample 
*sample,
                        break;
                case PERF_RECORD_SWITCH:
                case PERF_RECORD_SWITCH_CPU_WIDE:
-                       if (has(SWITCH_OUT))
+                       if (has(SWITCH_OUT)) {
                                ret += fprintf(fp, "S");
+                               if (sample->misc & 
PERF_RECORD_MISC_SWITCH_OUT_PREEMPT)
+                                       ret += fprintf(fp, "p");
+                       }
                default:
                        break;
                }