CVS commit: src/sys/kern

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Mon May 30 20:28:30 UTC 2022

Modified Files:
        src/sys/kern: subr_kmem.c

Log Message:
kmem(9): Create dtrace sdt probes for each kmem cache size.

The names of the probes correspond to the names shown in vmstat -m.
This should make it much easier to track down who's allocating memory
when there's a leak, e.g. by getting a histogram of stack traces for
the matching kmem cache pool:

   # vmstat -m
   Memory resource pool statistics
   Name        Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
   ...
   kmem-00128   256    62242    0        0  3891     0  3891  3891     0   inf    0
   ...
   # dtrace -n 'sdt:kmem:*:kmem-00128 { @[probefunc, stack()] = count() }'
   ^C

When there's no leak, the allocs and frees (probefunc) will be roughly
matched; when there's a leak, the allocs will far outnumber the frees.


To generate a diff of this commit:
cvs rdiff -u -r1.84 -r1.85 src/sys/kern/subr_kmem.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.