svn commit: r331518 - stable/11/lib/libutil

[Sevan Janiyan]

Author: sevan (doc committer)
Date: Sun Mar 25 01:34:44 2018
New Revision: 331518
URL: https://svnweb.freebsd.org/changeset/base/331518

Log:
  MFC r322665
  
  Add caveat to kinfo_getvmmap(3) explaining high CPU utilisation.
  Based on kib's reply on https://lists.freebsd.org/pipermail/freebsd-hackers/2016-July/049710.html

Modified:
  stable/11/lib/libutil/kinfo_getvmmap.3
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/lib/libutil/kinfo_getvmmap.3
==============================================================================
--- stable/11/lib/libutil/kinfo_getvmmap.3	Sun Mar 25 01:33:51 2018	(r331517)
+++ stable/11/lib/libutil/kinfo_getvmmap.3	Sun Mar 25 01:34:44 2018	(r331518)
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 27, 2015
+.Dd August 18, 2017
 .Dt KINFO_GETVMMAP 3
 .Os
 .Sh NAME
@@ -58,6 +58,13 @@ with the
 mib.
 While the kernel returns a packed structure, this function expands the
 data into a fixed record format.
+.Sh CAVEAT
+.Fn kinfo_getvmmap
+calls can cause significant CPU consumption because calculating the residency
+counts requires iterating over all memory pages of the process.
+Setting the sysctl variable
+.Va kern.proc_vmmap_skip_resident_count
+to 1 prevents this calculation.
 .Sh RETURN VALUES
 On success the
 .Fn kinfo_getvmmap