diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2019-09-23 15:34:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-24 15:54:07 -0700 |
| commit | c5665868183fec689dbab9fb8505188b2c4f0757 (patch) | |
| tree | 55c3277578a7444491e77fb3887e9783d3679e82 /lib/Kconfig.debug | |
| parent | 0647398a8c7bd55e0b7565c5076e86b7c3c204c5 (diff) | |
| download | lwn-c5665868183fec689dbab9fb8505188b2c4f0757.tar.gz lwn-c5665868183fec689dbab9fb8505188b2c4f0757.zip | |
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/Kconfig.debug')
| -rw-r--r-- | lib/Kconfig.debug | 11 |
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" |