Commit 3ddf20c9 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

srcu: Shrink Tiny SRCU a bit more 



This commit rearranges Tiny SRCU's srcu_struct structure, substitutes
u8 for bool, and shrinks counters down to short.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 41f36481

include/linux/srcutiny.h

+4 −4
Original line number Diff line number Diff line
@@ -27,15 +27,15 @@ 
#include <linux/swait.h>



struct srcu_struct {

	int srcu_lock_nesting[2];	/* srcu_read_lock() nesting depth. */

	short srcu_lock_nesting[2];	/* srcu_read_lock() nesting depth. */

	short srcu_idx;			/* Current reader array element. */

	u8 srcu_gp_running;		/* GP workqueue running? */

	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. */

	int srcu_idx;			/* Current reader array element. */

	bool srcu_gp_running;		/* GP workqueue running? */

	bool srcu_gp_waiting;		/* GP waiting for readers? */

	struct work_struct srcu_work;	/* For driving grace periods. */

#ifdef CONFIG_DEBUG_LOCK_ALLOC

	struct lockdep_map dep_map;

kernel/rcu/rcutorture.c

+1 −1
Original line number Diff line number Diff line
@@ -609,7 +609,7 @@ static void srcu_torture_stats(void) 
	pr_cont("\n");

#elif defined(CONFIG_TINY_SRCU)

	idx = READ_ONCE(srcu_ctlp->srcu_idx) & 0x1;

	pr_alert("%s%s Tiny SRCU per-CPU(idx=%d): (%d,%d)\n",

	pr_alert("%s%s Tiny SRCU per-CPU(idx=%d): (%hd,%hd)\n",

		 torture_type, TORTURE_FLAG, idx,

		 READ_ONCE(srcu_ctlp->srcu_lock_nesting[!idx]),

		 READ_ONCE(srcu_ctlp->srcu_lock_nesting[idx]));