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Diffstat (limited to 'Documentation/kmemleak.txt')
| -rw-r--r-- | Documentation/kmemleak.txt | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt index b6e39739a36..a7563ec4ea7 100644 --- a/Documentation/kmemleak.txt +++ b/Documentation/kmemleak.txt @@ -11,9 +11,7 @@ with the difference that the orphan objects are not freed but only 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 ----- @@ -53,7 +51,8 @@ Memory scanning parameters can be modified at run-time by writing to the (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 @@ -68,7 +67,7 @@ Basic Algorithm 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. @@ -84,7 +83,7 @@ The scanning algorithm steps: 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 @@ -120,6 +119,18 @@ Then as usual to get your report with: # 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 ------------ |