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Diffstat (limited to 'doc/SystemTap_Beginners_Guide')
| -rw-r--r-- | doc/SystemTap_Beginners_Guide/en-US/Scripts.xml | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml b/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml index 8426dc70..bbd265c2 100644 --- a/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml +++ b/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml @@ -122,6 +122,29 @@ probe timer.ms(4000) </listitem> </varlistentry> +<varlistentry> + <term>module("<replaceable>[module]</replaceable>").function("<replaceable>[function]</replaceable>")</term> + <listitem> + <para>Allows you to probe functions within modules. For example:</para> + +<example id="eventsmodules"><title>Module Probe</title> +<programlisting> +probe module("ext3").function("*") { }
+probe module("ext3").function("*").return { } +</programlisting> +</example> + + <para> + The first probe in <xref linkend="eventsmodules"/> points to the entry of <emphasis>all</emphasis> functions for the <filename>ext3</filename> module. The second probe points to the exits of all entries for that same module; the use of the <command>.return</command> suffix is similar to <command>kernel.function()</command>. Note that the probes in <xref linkend="eventsmodules"/> also do not contain probe bodies, and as such will not print any useful data (as in <xref linkend="wildcards"/>). + </para> + + <para> + A system's loaded modules are typically located in <filename>/lib/modules/<replaceable>[kernel version]</replaceable></filename>, where <replaceable>kernel version</replaceable> refers to the currently loaded kernel. Modules use the filename extension <filename>.ko</filename>. + </para> + + </listitem> +</varlistentry> + <!--<remark>add timer.ms() to events list!</remark>--> <!-- <varlistentry> @@ -278,6 +301,56 @@ hald(2360) open <para>If known, the name of the function in which the probe was placed.</para> </listitem> </varlistentry> + +<varlistentry> + <term>thread_indent()</term> + <listitem> + <para>This particular handler function is quite useful, providing you with a way to better organize your print results. When used with an indentation parameter (for example, <command>-1</command>), it allows the probe to internally store an "indentation counter" for each thread (identified by ID, as in <command>tid</command>). It then returns a string with some generic trace data along with an appropriate number of indentation spaces.</para> + + <para>The generic data included in the returned string includes a timestamp (number of microseconds since the most recent initial indentation), a process name, and the thread ID. This allows you to identify what functions were called, who called them, and the duration of each function call. + </para> + + <para> + Consider the following example on the use of <command>thread_indent()</command>: + </para> + +<example id="thread_indent"><title>Using thread_indent()</title> +<programlisting> +probe kernel.function("*@net/socket.c") +{ + printf ("%s -> %s\n", thread_indent(1), probefunc()) +} +probe kernel.function("*@net/socket.c").return +{ + printf ("%s <- %s\n", thread_indent(-1), probefunc()) +} +</programlisting> +</example> + <para><xref linkend="thread_indent"/> prints out the <command>thread_indent()</command> and probe functions at each event in the following format:</para> + +<screen> + 0 ftp(7223): -> sys_socketcall + 1159 ftp(7223): -> sys_socket + 2173 ftp(7223): -> __sock_create + 2286 ftp(7223): -> sock_alloc_inode + 2737 ftp(7223): <- sock_alloc_inode + 3349 ftp(7223): -> sock_alloc + 3389 ftp(7223): <- sock_alloc + 3417 ftp(7223): <- __sock_create + 4117 ftp(7223): -> sock_create + 4160 ftp(7223): <- sock_create + 4301 ftp(7223): -> sock_map_fd + 4644 ftp(7223): -> sock_map_file + 4699 ftp(7223): <- sock_map_file + 4715 ftp(7223): <- sock_map_fd + 4732 ftp(7223): <- sys_socket + 4775 ftp(7223): <- sys_socketcall +</screen> + +<remark>remember to add a reference later to "tapsets" from here, to clarify that thread_indent is defined in tapsets as a special function of sorts</remark> + + </listitem> +</varlistentry> <!-- <varlistentry> <term></term> |