The current value of the early boot static pool size is not big enough for systems with large number of CPUs with timer or/and workqueue objects selected. As the results, systems have 60+ CPUs with both timer and workqueue objects enabled could trigger "ODEBUG: Out of memory. ODEBUG disabled". Hence, fixed it by computing it according to CONFIG_NR_CPUS and CONFIG_DEBUG_OBJECTS_* options.
Signed-off-by: Qian Cai <c...@gmx.us> --- Changes since v1: * Removed the CONFIG_NR_CPUS check since it is always defined. * Introduced a minimal default pool size to start with. Otherwise, the pool size would be too low for systems only with a small number of CPUs. * Adjusted the scale factors according to data. lib/debugobjects.c | 81 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 79 insertions(+), 2 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 70935ed91125..a79f02c29617 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -23,9 +23,81 @@ #define ODEBUG_HASH_BITS 14 #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) -#define ODEBUG_POOL_SIZE 1024 +#define ODEBUG_DEFAULT_POOL 512 #define ODEBUG_POOL_MIN_LEVEL 256 +/* + * Some debug objects are allocated during the early boot. Enabling some + * options like timers or workqueue objects may increase the size required + * significantly with large number of CPUs. For example (as today, 20 Nov. + * 2018), + * + * No. CPUs x 2 (worker pool) objects: + * + * start_kernel + * workqueue_init_early + * init_worker_pool + * init_timer_key + * debug_object_init + * + * No. CPUs objects (CONFIG_HIGH_RES_TIMERS): + * + * sched_init + * hrtick_rq_init + * hrtimer_init + * + * CONFIG_DEBUG_OBJECTS_WORK: + * No. CPUs x 6 (workqueue) objects: + * + * workqueue_init_early + * alloc_workqueue + * __alloc_workqueue_key + * alloc_and_link_pwqs + * init_pwq + * + * Also, plus No. CPUs objects: + * + * perf_event_init + * __init_srcu_struct + * init_srcu_struct_fields + * init_srcu_struct_nodes + * __init_work + * + * Increase the number a bit more in case the implmentatins are changed in + * the future, as it is better to avoid OOM than spending a bit more kernel + * memory that will/can be freed. + */ +#if defined(CONFIG_DEBUG_OBJECTS_TIMERS) && \ +!defined(CONFIG_DEBUG_OBJECTS_WORK) +/* + * With all debug objects config options selected except workqueue, kernel + * reports, + * 64-CPU: ODEBUG: 466 of 466 active objects replaced + * 256-CPU: ODEBUG: 1810 of 1810 active objects replaced + */ +#define ODEBUG_POOL_SIZE (ODEBUG_DEFAULT_POOL + CONFIG_NR_CPUS * 10) + +#elif defined(CONFIG_DEBUG_OBJECTS_WORK) && \ +!defined(CONFIG_DEBUG_OBJECTS_TIMERS) +/* + * all the options except the timers: + * 64-CPU: ODEBUG: 652 of 652 active objects replaced + * 256-CPU: ODEBUG: 2572 of 2572 active objects replaced + */ +#define ODEBUG_POOL_SIZE (ODEBUG_DEFAULT_POOL + CONFIG_NR_CPUS * 10) + +#elif defined(CONFIG_DEBUG_OBJECTS_WORK) && \ +defined(CONFIG_DEBUG_OBJECTS_TIMERS) +/* + * all the options: + * 64-CPU: ODEBUG: 1114 of 1114 active objects replaced + * 256-CPU: ODEBUG: 4378 of 4378 active objects replaced + */ +#define ODEBUG_POOL_SIZE (ODEBUG_DEFAULT_POOL + CONFIG_NR_CPUS * 20) +#else +#define ODEBUG_POOL_SIZE ODEBUG_DEFAULT_POOL +#endif + #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) @@ -58,8 +130,13 @@ static int debug_objects_fixups __read_mostly; static int debug_objects_warnings __read_mostly; static int debug_objects_enabled __read_mostly = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; +/* + * This is only used after replaced static objects, so no need to scale it + * to use the early boot static pool size and it has already been scaled + * according to actual No. CPUs in the box within debug_objects_mem_init(). + */ static int debug_objects_pool_size __read_mostly - = ODEBUG_POOL_SIZE; + = ODEBUG_DEFAULT_POOL; static int debug_objects_pool_min_level __read_mostly = ODEBUG_POOL_MIN_LEVEL; static struct debug_obj_descr *descr_test __read_mostly; -- 2.17.2 (Apple Git-113)