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authorCatalin Marinas <catalin.marinas@arm.com>2019-09-23 15:34:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-24 15:54:07 -0700
commitc5665868183fec689dbab9fb8505188b2c4f0757 (patch)
tree55c3277578a7444491e77fb3887e9783d3679e82 /lib
parent0647398a8c7bd55e0b7565c5076e86b7c3c204c5 (diff)
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mm: kmemleak: use the memory pool for early allocations
Currently kmemleak uses a static early_log buffer to trace all memory allocation/freeing before the slab allocator is initialised. Such early log is replayed during kmemleak_init() to properly initialise the kmemleak metadata for objects allocated up that point. With a memory pool that does not rely on the slab allocator, it is possible to skip this early log entirely. In order to remove the early logging, consider kmemleak_enabled == 1 by default while the kmem_cache availability is checked directly on the object_cache and scan_area_cache variables. The RCU callback is only invoked after object_cache has been initialised as we wouldn't have any concurrent list traversal before this. In order to reduce the number of callbacks before kmemleak is fully initialised, move the kmemleak_init() call to mm_init(). [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: remove WARN_ON(), per Catalin] Link: http://lkml.kernel.org/r/20190812160642.52134-4-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug11
1 files changed, 6 insertions, 5 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 3c88e54da86c..c6975cded461 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -576,17 +576,18 @@ config DEBUG_KMEMLEAK
In order to access the kmemleak file, debugfs needs to be
mounted (usually at /sys/kernel/debug).
-config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
- int "Maximum kmemleak early log entries"
+config DEBUG_KMEMLEAK_MEM_POOL_SIZE
+ int "Kmemleak memory pool size"
depends on DEBUG_KMEMLEAK
range 200 40000
default 16000
help
Kmemleak must track all the memory allocations to avoid
reporting false positives. Since memory may be allocated or
- freed before kmemleak is initialised, an early log buffer is
- used to store these actions. If kmemleak reports "early log
- buffer exceeded", please increase this value.
+ freed before kmemleak is fully initialised, use a static pool
+ of metadata objects to track such callbacks. After kmemleak is
+ fully initialised, this memory pool acts as an emergency one
+ if slab allocations fail.
config DEBUG_KMEMLEAK_TEST
tristate "Simple test for the kernel memory leak detector"