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Commit 14961444 authored by Paul E. McKenney's avatar Paul E. McKenney
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rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs 



TINY_RCU's reset_cpu_stall_ticks() and check_cpu_stalls() functions
are defined unconditionally, and are empty functions if CONFIG_RCU_TRACE
is disabled (which in turns disables detection of RCU CPU stalls).
This commit saves a few lines of source code by defining these functions
only if CONFIG_RCU_TRACE=y.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 2439b696

kernel/rcutiny.c

+2 −2
Original line number Diff line number Diff line
@@ -204,7 +204,7 @@ static int rcu_is_cpu_rrupt_from_idle(void) 
 */

static int rcu_qsctr_help(struct rcu_ctrlblk *rcp)

{

	reset_cpu_stall_ticks(rcp);

	RCU_TRACE(reset_cpu_stall_ticks(rcp));

	if (rcp->rcucblist != NULL &&

	    rcp->donetail != rcp->curtail) {

		rcp->donetail = rcp->curtail;
@@ -251,7 +251,7 @@ void rcu_bh_qs(int cpu) 
 */

void rcu_check_callbacks(int cpu, int user)

{

	check_cpu_stalls();

	RCU_TRACE(check_cpu_stalls());

	if (user || rcu_is_cpu_rrupt_from_idle())

		rcu_sched_qs(cpu);

	else if (!in_softirq())

kernel/rcutiny_plugin.h

+2 −4
Original line number Diff line number Diff line
@@ -158,15 +158,11 @@ static void check_cpu_stall(struct rcu_ctrlblk *rcp) 
		rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();

}



#endif /* #ifdef CONFIG_RCU_TRACE */



static void reset_cpu_stall_ticks(struct rcu_ctrlblk *rcp)

{

#ifdef CONFIG_RCU_TRACE

	rcp->ticks_this_gp = 0;

	rcp->gp_start = jiffies;

	rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();

#endif /* #ifdef CONFIG_RCU_TRACE */

}



static void check_cpu_stalls(void)
@@ -174,3 +170,5 @@ static void check_cpu_stalls(void) 
	RCU_TRACE(check_cpu_stall(&rcu_bh_ctrlblk));

	RCU_TRACE(check_cpu_stall(&rcu_sched_ctrlblk));

}



#endif /* #ifdef CONFIG_RCU_TRACE */