Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / Documentation / kmemleak.txt

diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt
index 8906803..34f6638 100644 (file)
--- a/Documentation/kmemleak.txt
+++ b/Documentation/kmemleak.txt
@@ -27,6 +27,13 @@ To trigger an intermediate memory scan:
 
   # echo scan > /sys/kernel/debug/kmemleak
 
+To clear the list of all current possible memory leaks:
+
+  # echo clear > /sys/kernel/debug/kmemleak
+
+New leaks will then come up upon reading /sys/kernel/debug/kmemleak
+again.
+
 Note that the orphan objects are listed in the order they were allocated
 and one object at the beginning of the list may cause other subsequent
 objects to be reported as orphan.
@@ -42,6 +49,9 @@ Memory scanning parameters can be modified at run-time by writing to the
   scan=<secs>  - set the automatic memory scanning period in seconds
                  (default 600, 0 to stop the automatic scanning)
   scan         - trigger a memory scan
+  clear                - clear list of current memory leak suspects, done by
+                 marking all current reported unreferenced objects grey
+  dump=<addr>  - dump information about the object found at <addr>
 
 Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
 the kernel command line.
@@ -86,6 +96,27 @@ avoid this, kmemleak can also store the number of values pointing to an
 address inside the block address range that need to be found so that the
 block is not considered a leak. One example is __vmalloc().
 
+Testing specific sections with kmemleak
+---------------------------------------
+
+Upon initial bootup your /sys/kernel/debug/kmemleak output page may be
+quite extensive. This can also be the case if you have very buggy code
+when doing development. To work around these situations you can use the
+'clear' command to clear all reported unreferenced objects from the
+/sys/kernel/debug/kmemleak output. By issuing a 'scan' after a 'clear'
+you can find new unreferenced objects; this should help with testing
+specific sections of code.
+
+To test a critical section on demand with a clean kmemleak do:
+
+  # echo clear > /sys/kernel/debug/kmemleak
+  ... test your kernel or modules ...
+  # echo scan > /sys/kernel/debug/kmemleak
+
+Then as usual to get your report with:
+
+  # cat /sys/kernel/debug/kmemleak
+
 Kmemleak API
 ------------