powerpc64 (and more): procstat -kk does not report sched_switch, just mi_switch's call to it.

[Mark Millard]

Take, for example (from a powerpc64 context),

# procstat -kk 23
  PID    TID COMM                TDNAME              KSTACK                       
   23 100074 bufdaemon           -                   mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c buf_daemon+0x2f8 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100080 bufdaemon           bufspacedaemon-0    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100081 bufdaemon           bufspacedaemon-1    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100082 bufdaemon           bufspacedaemon-2    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100083 bufdaemon           bufspacedaemon-3    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100084 bufdaemon           bufspacedaemon-4    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100085 bufdaemon           bufspacedaemon-5    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100086 bufdaemon           bufspacedaemon-6    mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c bufspace_daemon+0x438 fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 
   23 100106 bufdaemon           / worker            mi_switch+0x134 sleepq_switch+0x2ec sleepq_timedwait+0x48 _sleep+0x41c softdep_flush+0x38c fork_exit+0xb0 fork_trampoline+0x18 .TOC.+0x1fffffff642c6efc 

then using objdump on /boot/kernel/kernel :

0000000000751868 <mi_switch+0x130> mr      r3,r30
000000000075186c <mi_switch+0x134> bl      0000000000789f14 <sched_switch+0x8>
0000000000751870 <mi_switch+0x138> nop

But I see the same sort of thing on amd6:

# procstat -kk 46
  PID    TID COMM                TDNAME              KSTACK                       
   46 100274 bufdaemon           -                   mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 buf_daemon+0x158 fork_exit+0xbd fork_trampoline+0xe 
   46 100275 bufdaemon           bufspacedaemon-0    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100277 bufdaemon           bufspacedaemon-1    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100279 bufdaemon           bufspacedaemon-2    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100280 bufdaemon           bufspacedaemon-3    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100282 bufdaemon           bufspacedaemon-4    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100283 bufdaemon           bufspacedaemon-5    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100284 bufdaemon           bufspacedaemon-6    mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 bufspace_daemon+0x4d6 fork_exit+0xbd fork_trampoline+0xe 
   46 100297 bufdaemon           / worker            mi_switch+0x131 sleepq_timedwait+0x36 _sleep+0x289 softdep_flush+0x2c9 fork_exit+0xbd fork_trampoline+0xe 


ffffffff81139d0c <mi_switch+0x12c> callq  ffffffff81177760 <sched_switch>
ffffffff81139d11 <mi_switch+0x131> mov    %gs:0x18,%rbx


Is this lack of listing sched_switch information intended behavior?



Note for powerpc64 relative to the "+8":

0000000000789f0c <sched_switch> addis   r2,r12,190
0000000000789f10 <sched_switch+0x4> addi    r2,r2,-12044
0000000000789f14 <sched_switch+0x8> mflr    r0
0000000000789f18 <sched_switch+0xc> std     r0,16(r1)



===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)