Date: Fri, 18 Aug 2017 16:42:58 +0000 (UTC) From: Sevan Janiyan <sevan@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r322665 - head/lib/libutil Message-ID: <201708181642.v7IGgw2g023582@repo.freebsd.org>
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Author: sevan (doc committer) Date: Fri Aug 18 16:42:58 2017 New Revision: 322665 URL: https://svnweb.freebsd.org/changeset/base/322665 Log: 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 PR: 210904 Submitted by: Yuri Victorovich <yuri AT rawbw DOT com> Reviewed by: jilles Approved by: bcr (mentor) MFC after: 5 days Differential Revision: https://reviews.freebsd.org/D12004 Modified: head/lib/libutil/kinfo_getvmmap.3 Modified: head/lib/libutil/kinfo_getvmmap.3 ============================================================================== --- head/lib/libutil/kinfo_getvmmap.3 Fri Aug 18 16:38:33 2017 (r322664) +++ head/lib/libutil/kinfo_getvmmap.3 Fri Aug 18 16:42:58 2017 (r322665) @@ -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
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