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-rw-r--r--kernel/rcu/tiny.c54
1 files changed, 18 insertions, 36 deletions
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index e5385731e391..f8488965250f 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -35,15 +35,26 @@
#include <linux/time.h>
#include <linux/cpu.h>
#include <linux/prefetch.h>
-#include <linux/trace_events.h>
#include "rcu.h"
-/* Forward declarations for tiny_plugin.h. */
-struct rcu_ctrlblk;
-static void __call_rcu(struct rcu_head *head,
- rcu_callback_t func,
- struct rcu_ctrlblk *rcp);
+/* Global control variables for rcupdate callback mechanism. */
+struct rcu_ctrlblk {
+ struct rcu_head *rcucblist; /* List of pending callbacks (CBs). */
+ struct rcu_head **donetail; /* ->next pointer of last "done" CB. */
+ struct rcu_head **curtail; /* ->next pointer of last CB. */
+};
+
+/* Definition for rcupdate control block. */
+static struct rcu_ctrlblk rcu_sched_ctrlblk = {
+ .donetail = &rcu_sched_ctrlblk.rcucblist,
+ .curtail = &rcu_sched_ctrlblk.rcucblist,
+};
+
+static struct rcu_ctrlblk rcu_bh_ctrlblk = {
+ .donetail = &rcu_bh_ctrlblk.rcucblist,
+ .curtail = &rcu_bh_ctrlblk.rcucblist,
+};
#include "tiny_plugin.h"
@@ -59,19 +70,6 @@ void rcu_barrier_sched(void)
}
EXPORT_SYMBOL(rcu_barrier_sched);
-#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
-
-/*
- * Test whether RCU thinks that the current CPU is idle.
- */
-bool notrace __rcu_is_watching(void)
-{
- return true;
-}
-EXPORT_SYMBOL(__rcu_is_watching);
-
-#endif /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
-
/*
* Helper function for rcu_sched_qs() and rcu_bh_qs().
* Also irqs are disabled to avoid confusion due to interrupt handlers
@@ -79,7 +77,6 @@ EXPORT_SYMBOL(__rcu_is_watching);
*/
static int rcu_qsctr_help(struct rcu_ctrlblk *rcp)
{
- RCU_TRACE(reset_cpu_stall_ticks(rcp);)
if (rcp->donetail != rcp->curtail) {
rcp->donetail = rcp->curtail;
return 1;
@@ -125,7 +122,6 @@ void rcu_bh_qs(void)
*/
void rcu_check_callbacks(int user)
{
- RCU_TRACE(check_cpu_stalls();)
if (user)
rcu_sched_qs();
else if (!in_softirq())
@@ -140,10 +136,8 @@ void rcu_check_callbacks(int user)
*/
static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
{
- const char *rn = NULL;
struct rcu_head *next, *list;
unsigned long flags;
- RCU_TRACE(int cb_count = 0;)
/* Move the ready-to-invoke callbacks to a local list. */
local_irq_save(flags);
@@ -152,7 +146,6 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
local_irq_restore(flags);
return;
}
- RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1);)
list = rcp->rcucblist;
rcp->rcucblist = *rcp->donetail;
*rcp->donetail = NULL;
@@ -162,22 +155,15 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
local_irq_restore(flags);
/* Invoke the callbacks on the local list. */
- RCU_TRACE(rn = rcp->name;)
while (list) {
next = list->next;
prefetch(next);
debug_rcu_head_unqueue(list);
local_bh_disable();
- __rcu_reclaim(rn, list);
+ __rcu_reclaim("", list);
local_bh_enable();
list = next;
- RCU_TRACE(cb_count++;)
}
- RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count);)
- RCU_TRACE(trace_rcu_batch_end(rcp->name,
- cb_count, 0, need_resched(),
- is_idle_task(current),
- false));
}
static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
@@ -221,7 +207,6 @@ static void __call_rcu(struct rcu_head *head,
local_irq_save(flags);
*rcp->curtail = head;
rcp->curtail = &head->next;
- RCU_TRACE(rcp->qlen++;)
local_irq_restore(flags);
if (unlikely(is_idle_task(current))) {
@@ -254,8 +239,5 @@ EXPORT_SYMBOL_GPL(call_rcu_bh);
void __init rcu_init(void)
{
open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
- RCU_TRACE(reset_cpu_stall_ticks(&rcu_sched_ctrlblk);)
- RCU_TRACE(reset_cpu_stall_ticks(&rcu_bh_ctrlblk);)
-
rcu_early_boot_tests();
}