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rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs

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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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
2013-04-16 07:49:22 -07:00
parent 2439b696cb
commit 1496144469
2 changed files with 4 additions and 6 deletions
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4
kernel/rcutiny.c
View File

@@ -204,7 +204,7 @@ static int rcu_is_cpu_rrupt_from_idle(void)
*/ */
static int rcu_qsctr_help(struct rcu_ctrlblk *rcp) 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 && if (rcp->rcucblist != NULL &&
rcp->donetail != rcp->curtail) { rcp->donetail != rcp->curtail) {
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) void rcu_check_callbacks(int cpu, int user)
{ {
check_cpu_stalls(); RCU_TRACE(check_cpu_stalls());
if (user || rcu_is_cpu_rrupt_from_idle()) if (user || rcu_is_cpu_rrupt_from_idle())
rcu_sched_qs(cpu); rcu_sched_qs(cpu);
else if (!in_softirq()) else if (!in_softirq())

6
kernel/rcutiny_plugin.h
View File

@@ -158,15 +158,11 @@ static void check_cpu_stall(struct rcu_ctrlblk *rcp)
rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check(); rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();
} }
#endif /* #ifdef CONFIG_RCU_TRACE */
static void reset_cpu_stall_ticks(struct rcu_ctrlblk *rcp) static void reset_cpu_stall_ticks(struct rcu_ctrlblk *rcp)
{ {
#ifdef CONFIG_RCU_TRACE
rcp->ticks_this_gp = 0; rcp->ticks_this_gp = 0;
rcp->gp_start = jiffies; rcp->gp_start = jiffies;
rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check(); rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();
#endif /* #ifdef CONFIG_RCU_TRACE */
} }
static void check_cpu_stalls(void) 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_bh_ctrlblk));
RCU_TRACE(check_cpu_stall(&rcu_sched_ctrlblk)); RCU_TRACE(check_cpu_stall(&rcu_sched_ctrlblk));
} }
#endif /* #ifdef CONFIG_RCU_TRACE */