xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

srcu: Apply trivial callback lists to shrink Tiny SRCU

Browse Source 
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>
This commit is contained in:
Paul E. McKenney
2017-05-04 14:29:16 -07:00
parent 5a0465e17a
commit 2464dd940e
4 changed files with 36 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/srcutiny.h
View File

@@ -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) \
}