Dtrace to get write size by distribution - macos

Question

I'm trying to get write size distribution by process. I ran:
sudo dtrace -n 'sysinfo:::writech { #dist[execname] = quantize(arg0); }'
and got the following error:
dtrace: invalid probe specifier sysinfo:::writech...
This is Mac OSX. Please help.

Answer 1

The error message is telling you that Mac OS X doesn't support the sysinfo::: provider. Perhaps you meant to use one of these?
# dtrace -ln sysinfo::writech:
ID PROVIDER MODULE FUNCTION NAME
dtrace: failed to match sysinfo::writech:: No probe matches description
# dtrace -ln sysinfo:::
ID PROVIDER MODULE FUNCTION NAME
dtrace: failed to match sysinfo:::: No probe matches description
# dtrace -ln 'syscall::write*:'
ID PROVIDER MODULE FUNCTION NAME
147 syscall write entry
148 syscall write return
381 syscall writev entry
382 syscall writev return
933 syscall write_nocancel entry
934 syscall write_nocancel return
963 syscall writev_nocancel entry
964 syscall writev_nocancel return
The following script works for me:
# dtrace -n 'syscall::write:entry {#dist[execname] = quantize(arg0)}'
dtrace: description 'syscall::write:entry ' matched 1 probe
^C
activitymonitor
value ------------- Distribution ------------- count
2 | 0
4 |######################################## 4
8 | 0
Activity Monito
value ------------- Distribution ------------- count
2 | 0
4 |######################################## 6
8 | 0
...