[PATCH] debugobjects: add a new Kconfig for POOL_SIZE

Qian Cai
2018-11-18T08:23:19Z

The current value of ODEBUG_POOL_SIZE is not big enough for large memory
systems with timer or/and workqueue objects because during the early
boot, timer objects needs at least the size equals to

No. CPUs x 2 (worker pool)

start_kernel
workqueue_init_early
init_worker_pool
init_timer_key
debug_object_init

puls, No. CPUs

start_kernel
sched_init
hrtimer_init
debug_object_init

Then, workqueue objects requires even more,

No. CPUs x 2 (worker pool) x 6 (workqueue)

start_kernel
workqueue_init_early
__alloc_workqueue_key
alloc_workqueue
init_pwq
debug_object_init

plus, No, CPUs x 2 (worker pool)

start_kernel
perf_event_init
__init_srcu_struct
init_srcu_struct_fields
__init_work
debug_object_init

As the results, systems have 60+ CPUs with both timer and workqueue
objects enabled could trigger "ODEBUG: Out of memory. ODEBUG disabled".

Hence, add a new Kconfig option so users could adjust ODEBUG_POOL_SIZE
accordingly if either timer or workqueue objects are selected.

Signed-off-by: Qian Cai <cai@gmx.us>
---
lib/Kconfig.debug | 12 ++++++++++++
lib/debugobjects.c | 7 ++++++-
2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1af29b8224fd..a4af837649df 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -449,6 +449,18 @@ config DEBUG_OBJECTS
kernel to track the life time of various objects and validate
the operations on those objects.

+config DEBUG_OBJECTS_POOL_SIZE
+ int "Debug objects pool size"
+ depends on DEBUG_OBJECTS_TIMERS || DEBUG_OBJECTS_WORK
+ default 1024
+ help
+ Some debug objects are allocated during the early boot. Enable some
+ config options may requires the sizes below,
+
+ DEBUG_OBJECTS_TIMERS: No. CPUs x 2 (worker pool) + No. CPUs (hrtimer)
+ DEBUG_OBJECTS_WORK: No. CPUs x 2 (worker pool) x 6 (workqueue) +
+ No. CPUs x 2 (worker pool)
+
config DEBUG_OBJECTS_SELFTEST
bool "Debug objects selftest"
depends on DEBUG_OBJECTS
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 70935ed91125..eb8158538993 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -23,7 +23,12 @@
#define ODEBUG_HASH_BITS 14
#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)

-#define ODEBUG_POOL_SIZE 1024
+#ifdef CONFIG_DEBUG_OBJECTS_POOL_SIZE
+#define ODEBUG_POOL_SIZE CONFIG_DEBUG_OBJECTS_POOL_SIZE
+#else
+#define ODEBUG_POOL_SIZE 1024
+#endif
+
#define ODEBUG_POOL_MIN_LEVEL 256

#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
--
2.17.2 (Apple Git-113)