From: Frederic Weisbecker <[email protected]> This commit gathers the rcu_segcblist ->enabled and ->offloaded property field into a single ->flags bitmask to avoid further proliferation of individual u8 fields in the structure. This change prepares for the state formerly known as ->offloaded state to be modified at runtime.
Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Lai Jiangshan <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Neeraj Upadhyay <[email protected]> Cc: Thomas Gleixner <[email protected]> Inspired-by: Paul E. McKenney <[email protected]> Tested-by: Boqun Feng <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> --- include/linux/rcu_segcblist.h | 6 ++++-- kernel/rcu/rcu_segcblist.c | 6 +++--- kernel/rcu/rcu_segcblist.h | 23 +++++++++++++++++++++-- 3 files changed, 28 insertions(+), 7 deletions(-) diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h index 6c01f09..4714b02 100644 --- a/include/linux/rcu_segcblist.h +++ b/include/linux/rcu_segcblist.h @@ -63,6 +63,9 @@ struct rcu_cblist { #define RCU_NEXT_TAIL 3 #define RCU_CBLIST_NSEGS 4 +#define SEGCBLIST_ENABLED BIT(0) +#define SEGCBLIST_OFFLOADED BIT(1) + struct rcu_segcblist { struct rcu_head *head; struct rcu_head **tails[RCU_CBLIST_NSEGS]; @@ -73,8 +76,7 @@ struct rcu_segcblist { long len; #endif long seglen[RCU_CBLIST_NSEGS]; - u8 enabled; - u8 offloaded; + u8 flags; }; #define RCU_SEGCBLIST_INITIALIZER(n) \ diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c index 094de25..406c67b 100644 --- a/kernel/rcu/rcu_segcblist.c +++ b/kernel/rcu/rcu_segcblist.c @@ -246,7 +246,7 @@ void rcu_segcblist_init(struct rcu_segcblist *rsclp) rcu_segcblist_set_seglen(rsclp, i, 0); } rcu_segcblist_set_len(rsclp, 0); - rsclp->enabled = 1; + rcu_segcblist_set_flags(rsclp, SEGCBLIST_ENABLED); } /* @@ -257,7 +257,7 @@ void rcu_segcblist_disable(struct rcu_segcblist *rsclp) { WARN_ON_ONCE(!rcu_segcblist_empty(rsclp)); WARN_ON_ONCE(rcu_segcblist_n_cbs(rsclp)); - rsclp->enabled = 0; + rcu_segcblist_clear_flags(rsclp, SEGCBLIST_ENABLED); } /* @@ -266,7 +266,7 @@ void rcu_segcblist_disable(struct rcu_segcblist *rsclp) */ void rcu_segcblist_offload(struct rcu_segcblist *rsclp) { - rsclp->offloaded = 1; + rcu_segcblist_set_flags(rsclp, SEGCBLIST_OFFLOADED); } /* diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h index 18e101d..ff372db 100644 --- a/kernel/rcu/rcu_segcblist.h +++ b/kernel/rcu/rcu_segcblist.h @@ -53,19 +53,38 @@ static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp) #endif } +static inline void rcu_segcblist_set_flags(struct rcu_segcblist *rsclp, + int flags) +{ + rsclp->flags |= flags; +} + +static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp, + int flags) +{ + rsclp->flags &= ~flags; +} + +static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp, + int flags) +{ + return READ_ONCE(rsclp->flags) & flags; +} + /* * Is the specified rcu_segcblist enabled, for example, not corresponding * to an offline CPU? */ static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp) { - return rsclp->enabled; + return rcu_segcblist_test_flags(rsclp, SEGCBLIST_ENABLED); } /* Is the specified rcu_segcblist offloaded? */ static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp) { - return IS_ENABLED(CONFIG_RCU_NOCB_CPU) && rsclp->offloaded; + return IS_ENABLED(CONFIG_RCU_NOCB_CPU) && + rcu_segcblist_test_flags(rsclp, SEGCBLIST_OFFLOADED); } /* -- 2.9.5
