reported via /sys/kernel/debug/kmemleak. A similar method is used by the
Valgrind tool (memcheck --leak-check) to detect the memory leaks in
user-space applications.
-
-Please check DEBUG_KMEMLEAK dependencies in lib/Kconfig.debug for supported
-architectures.
+Kmemleak is supported on x86, arm, powerpc, sparc, sh, microblaze, ppc, mips, s390, metag and tile.
Usage
-----
(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
+ marking all current reported unreferenced objects grey,
+ or free all kmemleak objects if kmemleak has been disabled.
dump=<addr> - dump information about the object found at <addr>
Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
The memory allocations via kmalloc, vmalloc, kmem_cache_alloc and
friends are traced and the pointers, together with additional
-information like size and stack trace, are stored in a prio search tree.
+information like size and stack trace, are stored in a rbtree.
The corresponding freeing function calls are tracked and the pointers
removed from the kmemleak data structures.
1. mark all objects as white (remaining white objects will later be
considered orphan)
2. scan the memory starting with the data section and stacks, checking
- the values against the addresses stored in the prio search tree. If
+ the values against the addresses stored in the rbtree. If
a pointer to a white object is found, the object is added to the
gray list
3. scan the gray objects for matching addresses (some white objects
# cat /sys/kernel/debug/kmemleak
+Freeing kmemleak internal objects
+---------------------------------
+
+To allow access to previosuly found memory leaks after kmemleak has been
+disabled by the user or due to an fatal error, internal kmemleak objects
+won't be freed when kmemleak is disabled, and those objects may occupy
+a large part of physical memory.
+
+In this situation, you may reclaim memory with:
+
+ # echo clear > /sys/kernel/debug/kmemleak
+
Kmemleak API
------------