diff options
-rw-r--r-- | include/linux/rcupdate.h | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index e22960ecb71a..75921b83c0ab 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h | |||
@@ -97,6 +97,11 @@ extern struct lockdep_map rcu_sched_lock_map; | |||
97 | # define rcu_read_release_sched() \ | 97 | # define rcu_read_release_sched() \ |
98 | lock_release(&rcu_sched_lock_map, 1, _THIS_IP_) | 98 | lock_release(&rcu_sched_lock_map, 1, _THIS_IP_) |
99 | 99 | ||
100 | static inline int debug_lockdep_rcu_enabled(void) | ||
101 | { | ||
102 | return likely(rcu_scheduler_active && debug_locks); | ||
103 | } | ||
104 | |||
100 | /** | 105 | /** |
101 | * rcu_read_lock_held - might we be in RCU read-side critical section? | 106 | * rcu_read_lock_held - might we be in RCU read-side critical section? |
102 | * | 107 | * |
@@ -104,12 +109,14 @@ extern struct lockdep_map rcu_sched_lock_map; | |||
104 | * an RCU read-side critical section. In absence of CONFIG_PROVE_LOCKING, | 109 | * an RCU read-side critical section. In absence of CONFIG_PROVE_LOCKING, |
105 | * this assumes we are in an RCU read-side critical section unless it can | 110 | * this assumes we are in an RCU read-side critical section unless it can |
106 | * prove otherwise. | 111 | * prove otherwise. |
112 | * | ||
113 | * Check rcu_scheduler_active to prevent false positives during boot. | ||
107 | */ | 114 | */ |
108 | static inline int rcu_read_lock_held(void) | 115 | static inline int rcu_read_lock_held(void) |
109 | { | 116 | { |
110 | if (debug_locks) | 117 | if (!debug_lockdep_rcu_enabled()) |
111 | return lock_is_held(&rcu_lock_map); | 118 | return 1; |
112 | return 1; | 119 | return lock_is_held(&rcu_lock_map); |
113 | } | 120 | } |
114 | 121 | ||
115 | /** | 122 | /** |
@@ -119,12 +126,14 @@ static inline int rcu_read_lock_held(void) | |||
119 | * an RCU-bh read-side critical section. In absence of CONFIG_PROVE_LOCKING, | 126 | * an RCU-bh read-side critical section. In absence of CONFIG_PROVE_LOCKING, |
120 | * this assumes we are in an RCU-bh read-side critical section unless it can | 127 | * this assumes we are in an RCU-bh read-side critical section unless it can |
121 | * prove otherwise. | 128 | * prove otherwise. |
129 | * | ||
130 | * Check rcu_scheduler_active to prevent false positives during boot. | ||
122 | */ | 131 | */ |
123 | static inline int rcu_read_lock_bh_held(void) | 132 | static inline int rcu_read_lock_bh_held(void) |
124 | { | 133 | { |
125 | if (debug_locks) | 134 | if (!debug_lockdep_rcu_enabled()) |
126 | return lock_is_held(&rcu_bh_lock_map); | 135 | return 1; |
127 | return 1; | 136 | return lock_is_held(&rcu_bh_lock_map); |
128 | } | 137 | } |
129 | 138 | ||
130 | /** | 139 | /** |
@@ -135,15 +144,19 @@ static inline int rcu_read_lock_bh_held(void) | |||
135 | * this assumes we are in an RCU-sched read-side critical section unless it | 144 | * this assumes we are in an RCU-sched read-side critical section unless it |
136 | * can prove otherwise. Note that disabling of preemption (including | 145 | * can prove otherwise. Note that disabling of preemption (including |
137 | * disabling irqs) counts as an RCU-sched read-side critical section. | 146 | * disabling irqs) counts as an RCU-sched read-side critical section. |
147 | * | ||
148 | * Check rcu_scheduler_active to prevent false positives during boot. | ||
138 | */ | 149 | */ |
139 | #ifdef CONFIG_PREEMPT | 150 | #ifdef CONFIG_PREEMPT |
140 | static inline int rcu_read_lock_sched_held(void) | 151 | static inline int rcu_read_lock_sched_held(void) |
141 | { | 152 | { |
142 | int lockdep_opinion = 0; | 153 | int lockdep_opinion = 0; |
143 | 154 | ||
155 | if (!debug_lockdep_rcu_enabled()) | ||
156 | return 1; | ||
144 | if (debug_locks) | 157 | if (debug_locks) |
145 | lockdep_opinion = lock_is_held(&rcu_sched_lock_map); | 158 | lockdep_opinion = lock_is_held(&rcu_sched_lock_map); |
146 | return lockdep_opinion || preempt_count() != 0 || !rcu_scheduler_active; | 159 | return lockdep_opinion || preempt_count() != 0; |
147 | } | 160 | } |
148 | #else /* #ifdef CONFIG_PREEMPT */ | 161 | #else /* #ifdef CONFIG_PREEMPT */ |
149 | static inline int rcu_read_lock_sched_held(void) | 162 | static inline int rcu_read_lock_sched_held(void) |
@@ -174,7 +187,7 @@ static inline int rcu_read_lock_bh_held(void) | |||
174 | #ifdef CONFIG_PREEMPT | 187 | #ifdef CONFIG_PREEMPT |
175 | static inline int rcu_read_lock_sched_held(void) | 188 | static inline int rcu_read_lock_sched_held(void) |
176 | { | 189 | { |
177 | return preempt_count() != 0 || !rcu_scheduler_active; | 190 | return !rcu_scheduler_active || preempt_count() != 0; |
178 | } | 191 | } |
179 | #else /* #ifdef CONFIG_PREEMPT */ | 192 | #else /* #ifdef CONFIG_PREEMPT */ |
180 | static inline int rcu_read_lock_sched_held(void) | 193 | static inline int rcu_read_lock_sched_held(void) |
@@ -198,7 +211,7 @@ static inline int rcu_read_lock_sched_held(void) | |||
198 | */ | 211 | */ |
199 | #define rcu_dereference_check(p, c) \ | 212 | #define rcu_dereference_check(p, c) \ |
200 | ({ \ | 213 | ({ \ |
201 | if (debug_locks && !(c)) \ | 214 | if (debug_lockdep_rcu_enabled() && !(c)) \ |
202 | lockdep_rcu_dereference(__FILE__, __LINE__); \ | 215 | lockdep_rcu_dereference(__FILE__, __LINE__); \ |
203 | rcu_dereference_raw(p); \ | 216 | rcu_dereference_raw(p); \ |
204 | }) | 217 | }) |