From: Jim Cromie <[email protected]> Use struct folio_pool to dynamically expand lock dependency storage when the static list_entries pool is exhausted, avoiding premature lockdep disabling.
Signed-off-by: Jim Cromie <[email protected]> --- kernel/locking/lockdep.c | 35 ++++++++++++++++++++++++++++++++++- kernel/locking/lockdep_internals.h | 2 ++ kernel/locking/lockdep_proc.c | 16 ++++++++++++++-- 3 files changed, 50 insertions(+), 3 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 2d4c5bab5af8..f0f58db090ff 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -58,12 +58,37 @@ #include <linux/context_tracking.h> #include <linux/console.h> #include <linux/kasan.h> +#include <linux/folio_pool.h> + +DEFINE_STATIC_KEY_TRUE(lockdep_pool_key); +static struct folio_pool lockdep_pool = + FOLIO_POOL_INIT_KEY(lockdep_pool, sizeof(struct lock_list), + FOLIO_POOL_64K_ORDER, &lockdep_pool_key); + +static int __init setup_lockdep_folio_pool(char *str) +{ + bool enable; + + if (!kstrtobool(str, &enable)) { + if (enable) + static_branch_enable(&lockdep_pool_key); + else + static_branch_disable(&lockdep_pool_key); + } + return 1; +} +__setup("lockdep.folio_pool=", setup_lockdep_folio_pool); #include <asm/sections.h> #include "lockdep_internals.h" #include "lock_events.h" +void lockdep_pool_stats(unsigned int *nr_chunks, size_t *chunk_size, size_t *tail_used) +{ + folio_pool_stats(&lockdep_pool, nr_chunks, chunk_size, tail_used); +} + #include <trace/events/lock.h> #ifdef CONFIG_PROVE_LOCKING @@ -1404,11 +1429,19 @@ static struct lock_list *alloc_list_entry(void) ARRAY_SIZE(list_entries)); if (idx >= ARRAY_SIZE(list_entries)) { + struct lock_list *p; + + p = folio_pool_alloc_type(&lockdep_pool, struct lock_list, + GFP_ATOMIC); + if (p) { + nr_list_entries++; + return p; + } if (!debug_locks_off_graph_unlock()) return NULL; nbcon_cpu_emergency_enter(); - print_lockdep_off("BUG: MAX_LOCKDEP_ENTRIES too low!"); + print_lockdep_off("BUG: MAX_LOCKDEP_ENTRIES too low and folio_pool exhausted!"); dump_stack(); nbcon_cpu_emergency_exit(); return NULL; diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 0e5e6ffe91a3..f802160c0dd5 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -159,6 +159,8 @@ extern unsigned long max_lock_class_idx; extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; extern unsigned long lock_classes_in_use[]; +void lockdep_pool_stats(unsigned int *nr_chunks, size_t *chunk_size, size_t *tail_used); + #ifdef CONFIG_PROVE_LOCKING extern unsigned long lockdep_count_forward_deps(struct lock_class *); extern unsigned long lockdep_count_backward_deps(struct lock_class *); diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 1916db9aa46b..3e6f24ae9b34 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -288,8 +288,20 @@ static int lockdep_stats_show(struct seq_file *m, void *v) nr_lock_classes, MAX_LOCKDEP_KEYS); seq_printf(m, " dynamic-keys: %11lu\n", nr_dynamic_keys); - seq_printf(m, " direct dependencies: %11lu [max: %lu]\n", - nr_list_entries, MAX_LOCKDEP_ENTRIES); + { + unsigned int fp_chunks = 0; + size_t fp_chunk_sz = 0, fp_tail_used = 0; + + lockdep_pool_stats(&fp_chunks, &fp_chunk_sz, &fp_tail_used); + if (fp_chunks) { + seq_printf(m, " direct dependencies: %11lu [dynamic: %u x %zu kB, tail: %zu kB/%zu kB]\n", + nr_list_entries, fp_chunks, fp_chunk_sz / 1024, + fp_tail_used / 1024, fp_chunk_sz / 1024); + } else { + seq_printf(m, " direct dependencies: %11lu [max: %lu]\n", + nr_list_entries, MAX_LOCKDEP_ENTRIES); + } + } seq_printf(m, " indirect dependencies: %11lu\n", sum_forward_deps); -- 2.55.0
