Date: Tue, 5 May 2015 03:13:02 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r282444 - stable/10/share/man/man9 Message-ID: <201505050313.t453D3HT081905@svn.freebsd.org>
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Author: markj Date: Tue May 5 03:13:02 2015 New Revision: 282444 URL: https://svnweb.freebsd.org/changeset/base/282444 Log: MFC 281701: SDT(9): add a section on SDT providers, mentioning the "sdt" provider. Add examples demonstrating how one can list available providers and the DTrace probes provided by a provider. Modified: stable/10/share/man/man9/SDT.9 Directory Properties: stable/10/ (props changed) Modified: stable/10/share/man/man9/SDT.9 ============================================================================== --- stable/10/share/man/man9/SDT.9 Tue May 5 03:08:49 2015 (r282443) +++ stable/10/share/man/man9/SDT.9 Tue May 5 03:13:02 2015 (r282444) @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd March 8, 2015 +.Dd April 18, 2015 .Dt SDT 9 .Os .Sh NAME @@ -194,7 +194,37 @@ macros are used to create trace points. They are meant to be added to executable code and can be used to instrument the code in which they are called. +.Sh PROVIDERS +A number of kernel DTrace providers are available. +In general, these providers define stable interfaces and should be treated as +such: existing D scripts may be broken if a probe is renamed or its arguments +are modified. +However, it is often useful to define ad-hoc +.Nm +probes for debugging a subsystem or driver. +Similarly, a developer may wish to provide a group of +.Nm +probes without committing to their future stability. +Such probes should be added to the +.Ql sdt +provider instead of defining a new provider. .Sh EXAMPLES +The DTrace providers available on the current system can be listed with +.Bd -literal -offset indent +dtrace -l | sed 1d | awk '{print $2}' | sort -u +.Ed +.Pp +A detailed list of the probes offered by a given provider can be obtained by +specifying the provider using the +.Fl P +flag. +For example, to view the probes and argument types for the +.Ql sched +provider, run +.Bd -literal -offset indent +dtrace -lv -P sched +.Ed +.Pp The following probe definition will create a DTrace probe called .Ql icmp:::receive-unreachable , which would hypothetically be triggered when the kernel receives an ICMP packet
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