Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...

[linux.git] / kernel / rcu / tiny.c

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index e5385731e39109d9a27a47d123ac44908402fcce..f8488965250f12ce26d40ba31553b8128ef55023 100644 (file)
--- 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();
 }