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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-05-04 14:29:16 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-06-08 18:52:35 -0700 |
| commit | 2464dd940e23bad227c387a40eec99f7aa02ed96 (patch) | |
| tree | f6b03f085c113c47f4325a20b1829f43b7a46a5c /include/linux/srcutiny.h | |
| parent | 5a0465e17a18c467b712a816985b7b8dd8d10c16 (diff) | |
| download | lwn-2464dd940e23bad227c387a40eec99f7aa02ed96.tar.gz lwn-2464dd940e23bad227c387a40eec99f7aa02ed96.zip | |
srcu: Apply trivial callback lists to shrink Tiny SRCU
The rcu_segcblist structure provides quite a bit of functionality, and
Tiny SRCU needs almost none of it. So this commit replaces Tiny SRCU's
uses of rcu_segcblist with a simple singly linked list with tail pointer.
This change significantly reduces Tiny SRCU's memory footprint, more
than making up for the growth caused by the creation of rcu_segcblist.c
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include/linux/srcutiny.h')
| -rw-r--r-- | include/linux/srcutiny.h | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index 4c53e698c6e4..cfbfc540cafc 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -33,9 +33,8 @@ struct srcu_struct { u8 srcu_gp_waiting; /* GP waiting for readers? */ struct swait_queue_head srcu_wq; /* Last srcu_read_unlock() wakes GP. */ - unsigned long srcu_gp_seq; /* GP seq # for callback tagging. */ - struct rcu_segcblist srcu_cblist; - /* Pending SRCU callbacks. */ + struct rcu_head *srcu_cb_head; /* Pending callbacks: Head. */ + struct rcu_head **srcu_cb_tail; /* Pending callbacks: Tail. */ struct work_struct srcu_work; /* For driving grace periods. */ #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; @@ -47,7 +46,7 @@ void srcu_drive_gp(struct work_struct *wp); #define __SRCU_STRUCT_INIT(name) \ { \ .srcu_wq = __SWAIT_QUEUE_HEAD_INITIALIZER(name.srcu_wq), \ - .srcu_cblist = RCU_SEGCBLIST_INITIALIZER(name.srcu_cblist), \ + .srcu_cb_tail = &name.srcu_cb_head, \ .srcu_work = __WORK_INITIALIZER(name.srcu_work, srcu_drive_gp), \ __SRCU_DEP_MAP_INIT(name) \ } |