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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-08-06 15:16:57 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-09-20 21:16:21 -0700 |
| commit | 5b74c458906fc4a62f932ee8bb801d29baf15fec (patch) | |
| tree | b5fde68e681dc589e40347ee939a1433d70bd77a /kernel/rcu/tree.h | |
| parent | rcu: Invert passed_quiesce and rename to cpu_no_qs (diff) | |
| download | wireguard-linux-5b74c458906fc4a62f932ee8bb801d29baf15fec.tar.xz wireguard-linux-5b74c458906fc4a62f932ee8bb801d29baf15fec.zip | |
rcu: Make ->cpu_no_qs be a union for aggregate OR
This commit converts the rcu_data structure's ->cpu_no_qs field
to a union. The bytewise side of this union allows individual access
to indications as to whether this CPU needs to find a quiescent state
for a normal (.norm) and/or expedited (.exp) grace period. The setwise
side of the union allows testing whether or not a quiescent state is
needed at all, for either type of grace period.
For now, only .norm is used. A later commit will introduce the expedited
usage.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index ded4ceebed76..3eee48bcf52b 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -286,6 +286,18 @@ struct rcu_node { for ((rnp) = (rsp)->level[rcu_num_lvls - 1]; \ (rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++) +/* + * Union to allow "aggregate OR" operation on the need for a quiescent + * state by the normal and expedited grace periods. + */ +union rcu_noqs { + struct { + u8 norm; + u8 exp; + } b; /* Bits. */ + u16 s; /* Set of bits, aggregate OR here. */ +}; + /* Index values for nxttail array in struct rcu_data. */ #define RCU_DONE_TAIL 0 /* Also RCU_WAIT head. */ #define RCU_WAIT_TAIL 1 /* Also RCU_NEXT_READY head. */ @@ -302,7 +314,7 @@ struct rcu_data { /* is aware of having started. */ unsigned long rcu_qs_ctr_snap;/* Snapshot of rcu_qs_ctr to check */ /* for rcu_all_qs() invocations. */ - bool cpu_no_qs; /* No QS yet for this CPU. */ + union rcu_noqs cpu_no_qs; /* No QSes yet for this CPU. */ bool core_needs_qs; /* Core waits for quiesc state. */ bool beenonline; /* CPU online at least once. */ bool gpwrap; /* Possible gpnum/completed wrap. */ |