[kgtp] r998 committed - Update doc
- From: kgtp@xxxxxxxxxxxxxx
- To: kgtp@xxxxxxxxxxxxx
- Date: Wed, 28 Mar 2012 12:53:38 +0000
Revision: 998
Author: teawater
Date: Wed Mar 28 05:52:12 2012
Log: Update doc
http://code.google.com/p/kgtp/source/detail?r=998
Modified:
/wiki/HOWTO.wiki
=======================================
--- /wiki/HOWTO.wiki Wed Mar 28 05:48:47 2012
+++ /wiki/HOWTO.wiki Wed Mar 28 05:52:12 2012
@@ -502,13 +502,6 @@
$xtime_sec will access to the second part of a timespec.<br>
$xtime_nsec will access to the nanosecond part of a timespec.
-== How to use performance counters ==
-Performance counters are special hardware registers available on most
modern CPUs. These registers count the number of certain types of hw
events: such as instructions executed, cachemisses suffered, or branches
mis-predicted - without slowing down the kernel or applications. These
registers can also trigger interrupts when a threshold number of events
have passed - and can thus be used to profile the code that runs on that
CPU.<br>
-
-The Linux Performance Counter subsystem called perf event can get the
value of performance counter. You can access it through KGTP perf event
trace state variables.<br>
-
-Please goto read the file tools/perf/design.txt in Linux Kernel to get
more info about perf event.
-
== Howto backtrace (stack dump) ==
=== Collect stack and use GDB command "backtrace" ===
We can get a backtrace(stack dump) by collecting the stack.<br>
@@ -589,6 +582,14 @@
[22779.208140] [<c05b980d>] notify_die+0x2d/0x30
[22779.208142] [<c05b71c5>] do_int3+0x35/0xa0
}}}
+
+== How to use performance counters ==
+Performance counters are special hardware registers available on most
modern CPUs. These registers count the number of certain types of hw
events: such as instructions executed, cachemisses suffered, or branches
mis-predicted - without slowing down the kernel or applications. These
registers can also trigger interrupts when a threshold number of events
have passed - and can thus be used to profile the code that runs on that
CPU.<br>
+
+The Linux Performance Counter subsystem called perf event can get the
value of performance counter. You can access it through KGTP perf event
trace state variables.<br>
+
+Please goto read the file tools/perf/design.txt in Linux Kernel to get
more info about perf event.
+
=== Define a perf event trace state variable ===
Access an performance counter need define following trace state variable:
{{{
Other related posts:
- » [kgtp] r998 committed - Update doc - kgtp
