rcu: Open-code the rcu_cblist_n_cbs() function

Because the rcu_cblist_n_cbs() just samples the ->len counter, and
because the rcu_cblist structure is quite straightforward, it makes
sense to open-code rcu_cblist_n_cbs(p) as p->len, cutting out a level
of indirection.  This commit makes this change.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index 7d18d41f0116ce7b7c45deb5eab0f683a6e18f05..424a6b2309215deb30e663ab76167800b92b73f0 100644 (file)
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -22,12 +22,6 @@
 
 #include <linux/rcu_segcblist.h>
 
-/* Return number of callbacks in simple callback list. */
-static inline long rcu_cblist_n_cbs(struct rcu_cblist *rclp)
-{
-       return rclp->len;
-}
-
 /* Return number of lazy callbacks in simple callback list. */
 static inline long rcu_cblist_n_lazy_cbs(struct rcu_cblist *rclp)
 {

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 35152414760d8cff6aabf7460cdf24ca0a4698d0..942d529fccbc092b8f35b50a48c6a6b6070fd0df 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2633,9 +2633,8 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp, unsigned long flags)
                return;
 
        /* Do the accounting first. */
-       rdp->n_cbs_adopted += rcu_cblist_n_cbs(&rsp->orphan_done);
-       if (rcu_cblist_n_lazy_cbs(&rsp->orphan_done) !=
-           rcu_cblist_n_cbs(&rsp->orphan_done))
+       rdp->n_cbs_adopted += rsp->orphan_done.len;
+       if (rcu_cblist_n_lazy_cbs(&rsp->orphan_done) != rsp->orphan_done.len)
                rcu_idle_count_callbacks_posted();
        rcu_segcblist_insert_count(&rdp->cblist, &rsp->orphan_done);
 
@@ -2792,14 +2791,14 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
                 * Stop only if limit reached and CPU has something to do.
                 * Note: The rcl structure counts down from zero.
                 */
-               if (-rcu_cblist_n_cbs(&rcl) >= bl &&
+               if (-rcl.len >= bl &&
                    (need_resched() ||
                     (!is_idle_task(current) && !rcu_is_callbacks_kthread())))
                        break;
        }
 
        local_irq_save(flags);
-       count = -rcu_cblist_n_cbs(&rcl);
+       count = -rcl.len;
        trace_rcu_batch_end(rsp->name, count, !!rcl.head, need_resched(),
                            is_idle_task(current), rcu_is_callbacks_kthread());
 

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 6b4b1f8a272d745dfc749314aa49271a626686c8..7ebe357df155d45b927e4c1c653877e9c4fb0a34 100644 (file)
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1934,7 +1934,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp,
                                                     struct rcu_data *rdp,
                                                     unsigned long flags)
 {
-       long ql = rcu_cblist_n_cbs(&rsp->orphan_done);
+       long ql = rsp->orphan_done.len;
        long qll = rcu_cblist_n_lazy_cbs(&rsp->orphan_done);
 
        /* If this is not a no-CBs CPU, tell the caller to do it the old way. */

diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c
index 30c5bf89ee58f4b016ad09b63ff9097541055153..b7743aa2965fccdf943472e3181a0c582b297add 100644 (file)
--- a/kernel/rcu/tree_trace.c
+++ b/kernel/rcu/tree_trace.c
@@ -278,7 +278,7 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
                   rsp->n_force_qs - rsp->n_force_qs_ngp,
                   READ_ONCE(rsp->n_force_qs_lh),
                   rcu_cblist_n_lazy_cbs(&rsp->orphan_done),
-                  rcu_cblist_n_cbs(&rsp->orphan_done));
+                  rsp->orphan_done.len);
        for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
                if (rnp->level != level) {
                        seq_puts(m, "\n");