diff options
author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-28 14:16:16 -0700 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-06-08 08:25:38 -0700 |
commit | d4efe6c5ad91f9a1f2f1d66b7fbfc87e320b2abc (patch) | |
tree | 3f5aae932e67b13e70c516bee390ab83c087cdc7 /include/linux | |
parent | 07f6e64bf2ab98cad0d9c595659209858e7bff83 (diff) |
srcu: Shrink Tiny SRCU a bit
In Tiny SRCU, __srcu_read_lock() is a trivial function, outweighed by
its EXPORT_SYMBOL_GPL(), and on many architectures, its call sequence.
This commit therefore moves it to srcutiny.h so that it can be inlined.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/srcutiny.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index b8859179b001..b6edd9c8fdce 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -63,6 +63,21 @@ void srcu_drive_gp(struct work_struct *wp); void synchronize_srcu(struct srcu_struct *sp); +/* + * Counts the new reader in the appropriate per-CPU element of the + * srcu_struct. Can be invoked from irq/bh handlers, but the matching + * __srcu_read_unlock() must be in the same handler instance. Returns an + * index that must be passed to the matching srcu_read_unlock(). + */ +static inline int __srcu_read_lock(struct srcu_struct *sp) +{ + int idx; + + idx = READ_ONCE(sp->srcu_idx); + WRITE_ONCE(sp->srcu_lock_nesting[idx], sp->srcu_lock_nesting[idx] + 1); + return idx; +} + static inline void synchronize_srcu_expedited(struct srcu_struct *sp) { synchronize_srcu(sp); |