On 11/20/2018 09:11 PM, Qian Cai wrote: > 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 v3: > * style fixes > > Changes since v2: > * Made the calculation easier to read suggested by long...@redhat.com. > > 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..140571aa483c 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. > + * > + * With all debug objects config options selected except the workqueue and > the > + * timers, kernel reports, > + * 64-CPU: ODEBUG: 4 of 4 active objects replaced > + * 256-CPU: ODEBUG: 4 of 4 active objects replaced > + * > + * all the options except the workqueue: > + * 64-CPU: ODEBUG: 466 of 466 active objects replaced > + * 256-CPU: ODEBUG: 1810 of 1810 active objects replaced > + * > + * all the options except the timers: > + * 64-CPU: ODEBUG: 652 of 652 active objects replaced > + * 256-CPU: ODEBUG: 2572 of 2572 active objects replaced > + * > + * all the options: > + * 64-CPU: ODEBUG: 1114 of 1114 active objects replaced > + * 256-CPU: ODEBUG: 4378 of 4378 active objects replaced > + */ > +#ifdef CONFIG_DEBUG_OBJECTS_WORK > +#define ODEBUG_WORK_PCPU_CNT 10 > +#else > +#define ODEBUG_WORK_PCPU_CNT 0 > +#endif /* CONFIG_DEBUG_OBJECTS_WORK */ > + > +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS > +#define ODEBUG_TIMERS_PCPU_CNT 10 > +#else > +#define ODEBUG_TIMERS_PCPU_CNT 0 > +#endif /* CONFIG_DEBUG_OBJECTS_TIMERS */ > + > +#define ODEBUG_POOL_SIZE (ODEBUG_DEFAULT_POOL + CONFIG_NR_CPUS * \ > + (ODEBUG_TIMERS_PCPU_CNT + ODEBUG_WORK_PCPU_CNT)) > + > #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;
Acked-by: Waiman Long <long...@redhat.com>
