Currently if kmemleak is disabled, the kmemleak objects can never be
freed, no matter if it's disabled by a user or due to fatal errors.
Those objects can be a big waste of memory.
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
1200264 1197433 99% 0.30K 46164 26 369312K kmemleak_object
With this patch, after kmemleak was disabled you can reclaim memory
with:
# echo clear > /sys/kernel/debug/kmemleak
Also inform users about this with a printk.
Change-Id: I13fdd5f0439bf6bc23824d37a44813eb0fe6a392
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: c89da70c7360294e715df5abd4b7239db3274c86
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/
Signed-off-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org>
This patch adds kmemleak callbacks from the percpu allocator, reducing a
number of false positives caused by kmemleak not scanning such memory
blocks. The percpu chunks are never reported as leaks because of current
kmemleak limitations with the __percpu pointer not pointing directly to
the actual chunks.
Reported-by: Huajun Li <huajun.li.lee@gmail.com>
Acked-by: Christoph Lameter <cl@gentwo.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Instead of listing the architectures that are supported by
kmemleak in Documentation/kmemleak.txt, just refer people to
the list of supported architecutures in lib/Kconfig.debug so
that Documentation/kmemleak.txt does not need more updates
for this.
Signed-off-by: Maxin B. John <maxin.john@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Besides x86 and arm, kmemleak now supports powerpc, sparc, sh,
microblaze and tile.
Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In an ideal world your kmemleak output will be small, when its
not (usually during initial bootup) you can use the clear command
to ingore previously reported and unreferenced kmemleak objects. We
do this by painting all currently reported unreferenced objects grey.
We paint them grey instead of black to allow future scans on the same
objects as such objects could still potentially reference newly
allocated objects in the future.
To test a critical section on demand with a clean
/sys/kernel/debug/kmemleak you can 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
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
By writing dump=<addr> to the kmemleak file, kmemleak will look up an
object with that address and dump the information it has about it to
syslog. This is useful in debugging memory leaks.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Since there is a kernel thread for automatically scanning the memory, it
makes sense for the debug/kmemleak file to only show its findings. This
patch also adds support for "echo scan > debug/kmemleak" to trigger an
intermediate memory scan and eliminates the kmemleak_mutex (scan_mutex
covers all the cases now).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Because of false positives, the memory scanning thread may print too
much information. This patch changes the scanning thread to only print
the number of newly suspected leaks. Further information can be read
from the /sys/kernel/debug/kmemleak file.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(feature suggested by Sergey Senozhatsky)
Kmemleak needs to track all the memory allocations but some of these
happen before kmemleak is initialised. These are stored in an internal
buffer which may be exceeded in some kernel configurations. This patch
adds a configuration option with a default value of 400 and also removes
the stack dump when the early log buffer is exceeded.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
This patch adds the Documentation/kmemleak.txt file with some
information about how kmemleak works.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Li Zefan
Catalin Marinas
Maxin B. John
Daniel Baluta
Luis R. Rodriguez