diff options
Diffstat (limited to 'include/linux/srcutree.h')
| -rw-r--r-- | include/linux/srcutree.h | 94 |
1 files changed, 65 insertions, 29 deletions
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 558057b517b7..8f3f72480e78 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -58,9 +58,9 @@ struct srcu_node { }; /* - * Per-SRCU-domain structure, similar in function to rcu_state. + * Per-SRCU-domain structure, update-side data linked from srcu_struct. */ -struct srcu_struct { +struct srcu_usage { struct srcu_node *node; /* Combining tree. */ struct srcu_node *level[RCU_NUM_LVLS + 1]; /* First node at each level. */ @@ -68,7 +68,6 @@ struct srcu_struct { struct mutex srcu_cb_mutex; /* Serialize CB preparation. */ spinlock_t __private lock; /* Protect counters and size state. */ struct mutex srcu_gp_mutex; /* Serialize GP work. */ - unsigned int srcu_idx; /* Current rdr array element. */ unsigned long srcu_gp_seq; /* Grace-period seq #. */ unsigned long srcu_gp_seq_needed; /* Latest gp_seq needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ @@ -77,7 +76,6 @@ struct srcu_struct { unsigned long srcu_size_jiffies; /* Current contention-measurement interval. */ unsigned long srcu_n_lock_retries; /* Contention events in current interval. */ unsigned long srcu_n_exp_nodelay; /* # expedited no-delays in current GP phase. */ - struct srcu_data __percpu *sda; /* Per-CPU srcu_data array. */ bool sda_is_static; /* May ->sda be passed to free_percpu()? */ unsigned long srcu_barrier_seq; /* srcu_barrier seq #. */ struct mutex srcu_barrier_mutex; /* Serialize barrier ops. */ @@ -89,32 +87,68 @@ struct srcu_struct { unsigned long reschedule_jiffies; unsigned long reschedule_count; struct delayed_work work; + struct srcu_struct *srcu_ssp; +}; + +/* + * Per-SRCU-domain structure, similar in function to rcu_state. + */ +struct srcu_struct { + unsigned int srcu_idx; /* Current rdr array element. */ + struct srcu_data __percpu *sda; /* Per-CPU srcu_data array. */ struct lockdep_map dep_map; + struct srcu_usage *srcu_sup; /* Update-side data. */ }; -/* Values for size state variable (->srcu_size_state). */ -#define SRCU_SIZE_SMALL 0 -#define SRCU_SIZE_ALLOC 1 -#define SRCU_SIZE_WAIT_BARRIER 2 -#define SRCU_SIZE_WAIT_CALL 3 -#define SRCU_SIZE_WAIT_CBS1 4 -#define SRCU_SIZE_WAIT_CBS2 5 -#define SRCU_SIZE_WAIT_CBS3 6 -#define SRCU_SIZE_WAIT_CBS4 7 -#define SRCU_SIZE_BIG 8 +// Values for size state variable (->srcu_size_state). Once the state +// has been set to SRCU_SIZE_ALLOC, the grace-period code advances through +// this state machine one step per grace period until the SRCU_SIZE_BIG state +// is reached. Otherwise, the state machine remains in the SRCU_SIZE_SMALL +// state indefinitely. +#define SRCU_SIZE_SMALL 0 // No srcu_node combining tree, ->node == NULL +#define SRCU_SIZE_ALLOC 1 // An srcu_node tree is being allocated, initialized, + // and then referenced by ->node. It will not be used. +#define SRCU_SIZE_WAIT_BARRIER 2 // The srcu_node tree starts being used by everything + // except call_srcu(), especially by srcu_barrier(). + // By the end of this state, all CPUs and threads + // are aware of this tree's existence. +#define SRCU_SIZE_WAIT_CALL 3 // The srcu_node tree starts being used by call_srcu(). + // By the end of this state, all of the call_srcu() + // invocations that were running on a non-boot CPU + // and using the boot CPU's callback queue will have + // completed. +#define SRCU_SIZE_WAIT_CBS1 4 // Don't trust the ->srcu_have_cbs[] grace-period +#define SRCU_SIZE_WAIT_CBS2 5 // sequence elements or the ->srcu_data_have_cbs[] +#define SRCU_SIZE_WAIT_CBS3 6 // CPU-bitmask elements until all four elements of +#define SRCU_SIZE_WAIT_CBS4 7 // each array have been initialized. +#define SRCU_SIZE_BIG 8 // The srcu_node combining tree is fully initialized + // and all aspects of it are being put to use. /* Values for state variable (bottom bits of ->srcu_gp_seq). */ #define SRCU_STATE_IDLE 0 #define SRCU_STATE_SCAN1 1 #define SRCU_STATE_SCAN2 2 -#define __SRCU_STRUCT_INIT(name, pcpu_name) \ -{ \ - .sda = &pcpu_name, \ - .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ - .srcu_gp_seq_needed = -1UL, \ - .work = __DELAYED_WORK_INITIALIZER(name.work, NULL, 0), \ - __SRCU_DEP_MAP_INIT(name) \ +#define __SRCU_USAGE_INIT(name) \ +{ \ + .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ + .srcu_gp_seq_needed = -1UL, \ + .work = __DELAYED_WORK_INITIALIZER(name.work, NULL, 0), \ +} + +#define __SRCU_STRUCT_INIT_COMMON(name, usage_name) \ + .srcu_sup = &usage_name, \ + __SRCU_DEP_MAP_INIT(name) + +#define __SRCU_STRUCT_INIT_MODULE(name, usage_name) \ +{ \ + __SRCU_STRUCT_INIT_COMMON(name, usage_name) \ +} + +#define __SRCU_STRUCT_INIT(name, usage_name, pcpu_name) \ +{ \ + .sda = &pcpu_name, \ + __SRCU_STRUCT_INIT_COMMON(name, usage_name) \ } /* @@ -137,16 +171,18 @@ struct srcu_struct { * See include/linux/percpu-defs.h for the rules on per-CPU variables. */ #ifdef MODULE -# define __DEFINE_SRCU(name, is_static) \ - is_static struct srcu_struct name; \ - extern struct srcu_struct * const __srcu_struct_##name; \ - struct srcu_struct * const __srcu_struct_##name \ +# define __DEFINE_SRCU(name, is_static) \ + static struct srcu_usage name##_srcu_usage = __SRCU_USAGE_INIT(name##_srcu_usage); \ + is_static struct srcu_struct name = __SRCU_STRUCT_INIT_MODULE(name, name##_srcu_usage); \ + extern struct srcu_struct * const __srcu_struct_##name; \ + struct srcu_struct * const __srcu_struct_##name \ __section("___srcu_struct_ptrs") = &name #else -# define __DEFINE_SRCU(name, is_static) \ - static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data); \ - is_static struct srcu_struct name = \ - __SRCU_STRUCT_INIT(name, name##_srcu_data) +# define __DEFINE_SRCU(name, is_static) \ + static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data); \ + static struct srcu_usage name##_srcu_usage = __SRCU_USAGE_INIT(name##_srcu_usage); \ + is_static struct srcu_struct name = \ + __SRCU_STRUCT_INIT(name, name##_srcu_usage, name##_srcu_data) #endif #define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */) #define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static) |