diff options
Diffstat (limited to 'doc/SystemTap_Beginners_Guide')
3 files changed, 82 insertions, 2 deletions
diff --git a/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml b/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml index 7914e79c..92dd8f1c 100644 --- a/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml +++ b/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml @@ -430,7 +430,7 @@ probe syscall.* { <para>When <xref linkend="targetexample"/> is run with the argument <command>-x <replaceable>process ID</replaceable></command>, it watches all system calls (as specified by the event <command>syscall.*</command>) and prints out the name of all system calls made by the specified process.</para> - <para>This has the same effect as specifying <command>if (pid() == <replaceable>process ID</replaceable></command> each time you wish to target a specific process. However, using <command>target()</command> makes it easier for you to re-use the script, giving you the ability to simply pass a process ID as an argument each time you wish to run the script (e.g. <command>stap targetexample.stp -x <replaceable>process ID</replaceable></command>).</para> + <para>This has the same effect as specifying <command>if (pid() == <replaceable>process ID</replaceable>)</command> each time you wish to target a specific process. However, using <command>target()</command> makes it easier for you to re-use the script, giving you the ability to simply pass a process ID as an argument each time you wish to run the script (e.g. <command>stap targetexample.stp -x <replaceable>process ID</replaceable></command>).</para> <!-- <note> <title>Note</title> diff --git a/doc/SystemTap_Beginners_Guide/en-US/Useful_Scripts-functioncalls.xml b/doc/SystemTap_Beginners_Guide/en-US/Useful_Scripts-functioncalls.xml new file mode 100644 index 00000000..d108e4fe --- /dev/null +++ b/doc/SystemTap_Beginners_Guide/en-US/Useful_Scripts-functioncalls.xml @@ -0,0 +1,80 @@ +<?xml version='1.0'?> +<!DOCTYPE section PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ +]> + + + <section id="countcallssect"> + <title>Counting Function Calls Made</title> + + +<remark> + WAR STORY: Function call count http://sourceware.org/systemtap/wiki/WSFunctionCallCount?highlight=((WarStories)) +</remark> + +<remark> +no script in examples +</remark> + + + <para>This section describes how to identify how many times the system called a specific kernel function in a 30-second sample. Depending on your use of wildcards, you can also use this script to target multiple kernel functions.</para> + +<formalpara id="countcalls"> + <title>countcalls.stp</title> +<para> +<programlisting> +probe kernel.function(@1) { # probe every function in any C file under mm/ +called[probefunc()] <<< 1 # add a count efficiently +} +global called +probe end,timer.ms(30000) { + foreach (fn+ in called) # Sort by function name + # (fn in called-) # Sort by call count (in decreasing order) + printf("%s %d\n", fn, @count(called[fn])) + exit() +} +</programlisting> +</para> +</formalpara> + +<para><xref linkend="countcalls"/> takes the targeted kernel function as an argument. The argument supports wildcards, which enables you to target multiple kernel functions up to a certain extent.</para> + +<para>You can increase the sample time by editing the timer in the second probe (<command>timer.ms()</command>). <xref linkend="countcallsoutput"/> contains an excerpt from the output of <command>stap countcalls.stp "*@mm/*.c"</command>: + + +<example id="countcallsoutput"> + <title><xref linkend="countcalls"/> Sample Output</title> +<screen> +[...] +__vma_link 97 +__vma_link_file 66 +__vma_link_list 97 +__vma_link_rb 97 +__xchg 103 +add_page_to_active_list 102 +add_page_to_inactive_list 19 +add_to_page_cache 19 +add_to_page_cache_lru 7 +all_vm_events 6 +alloc_pages_node 4630 +alloc_slabmgmt 67 +anon_vma_alloc 62 +anon_vma_free 62 +anon_vma_lock 66 +anon_vma_prepare 98 +anon_vma_unlink 97 +anon_vma_unlock 66 +arch_get_unmapped_area_topdown 94 +arch_get_unmapped_exec_area 3 +arch_unmap_area_topdown 97 +atomic_add 2 +atomic_add_negative 97 +atomic_dec_and_test 5153 +atomic_inc 470 +atomic_inc_and_test 1 +[...] +</screen> +</example> + + + </section> + diff --git a/doc/SystemTap_Beginners_Guide/en-US/Useful_SystemTap_Scripts.xml b/doc/SystemTap_Beginners_Guide/en-US/Useful_SystemTap_Scripts.xml index d3d592ca..7145b622 100644 --- a/doc/SystemTap_Beginners_Guide/en-US/Useful_SystemTap_Scripts.xml +++ b/doc/SystemTap_Beginners_Guide/en-US/Useful_SystemTap_Scripts.xml @@ -28,7 +28,7 @@ <xi:include href="Useful_Scripts-paracallgraph.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="Useful_Scripts-inodewatch.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="Useful_Scripts-inodewatch2.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> - + <xi:include href="Useful_Scripts-functioncalls.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <!-- <xi:include href="Useful_Scripts-Network.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="Useful_Scripts-Signals.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="Useful_Scripts-Syscalls.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> |