srcu: Fix long lines in srcu_funnel_gp_start()

This commit creates an srcu_usage pointer named "sup" as a shorter
synonym for the "ssp->srcu_sup" that was bloating several lines of code.

Cc: Christoph Hellwig <hch@lst.de>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: "Zhang, Qiang1" <qiang1.zhang@intel.com>
Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index f661a0f6bc0dbd60ed00077b57a7da805fcece70..a887cfc898949f1b8836ff6fbb38de39773d4656 100644 (file)
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -1004,9 +1004,10 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
        struct srcu_node *snp;
        struct srcu_node *snp_leaf;
        unsigned long snp_seq;
+       struct srcu_usage *sup = ssp->srcu_sup;
 
        /* Ensure that snp node tree is fully initialized before traversing it */
-       if (smp_load_acquire(&ssp->srcu_sup->srcu_size_state) < SRCU_SIZE_WAIT_BARRIER)
+       if (smp_load_acquire(&sup->srcu_size_state) < SRCU_SIZE_WAIT_BARRIER)
                snp_leaf = NULL;
        else
                snp_leaf = sdp->mynode;
@@ -1014,7 +1015,7 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
        if (snp_leaf)
                /* Each pass through the loop does one level of the srcu_node tree. */
                for (snp = snp_leaf; snp != NULL; snp = snp->srcu_parent) {
-                       if (WARN_ON_ONCE(rcu_seq_done(&ssp->srcu_sup->srcu_gp_seq, s)) && snp != snp_leaf)
+                       if (WARN_ON_ONCE(rcu_seq_done(&sup->srcu_gp_seq, s)) && snp != snp_leaf)
                                return; /* GP already done and CBs recorded. */
                        spin_lock_irqsave_rcu_node(snp, flags);
                        snp_seq = snp->srcu_have_cbs[idx];
@@ -1041,20 +1042,20 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
 
        /* Top of tree, must ensure the grace period will be started. */
        spin_lock_irqsave_ssp_contention(ssp, &flags);
-       if (ULONG_CMP_LT(ssp->srcu_sup->srcu_gp_seq_needed, s)) {
+       if (ULONG_CMP_LT(sup->srcu_gp_seq_needed, s)) {
                /*
                 * Record need for grace period s.  Pair with load
                 * acquire setting up for initialization.
                 */
-               smp_store_release(&ssp->srcu_sup->srcu_gp_seq_needed, s); /*^^^*/
+               smp_store_release(&sup->srcu_gp_seq_needed, s); /*^^^*/
        }
-       if (!do_norm && ULONG_CMP_LT(ssp->srcu_sup->srcu_gp_seq_needed_exp, s))
-               WRITE_ONCE(ssp->srcu_sup->srcu_gp_seq_needed_exp, s);
+       if (!do_norm && ULONG_CMP_LT(sup->srcu_gp_seq_needed_exp, s))
+               WRITE_ONCE(sup->srcu_gp_seq_needed_exp, s);
 
        /* If grace period not already in progress, start it. */
-       if (!WARN_ON_ONCE(rcu_seq_done(&ssp->srcu_sup->srcu_gp_seq, s)) &&
-           rcu_seq_state(ssp->srcu_sup->srcu_gp_seq) == SRCU_STATE_IDLE) {
-               WARN_ON_ONCE(ULONG_CMP_GE(ssp->srcu_sup->srcu_gp_seq, ssp->srcu_sup->srcu_gp_seq_needed));
+       if (!WARN_ON_ONCE(rcu_seq_done(&sup->srcu_gp_seq, s)) &&
+           rcu_seq_state(sup->srcu_gp_seq) == SRCU_STATE_IDLE) {
+               WARN_ON_ONCE(ULONG_CMP_GE(sup->srcu_gp_seq, sup->srcu_gp_seq_needed));
                srcu_gp_start(ssp);
 
                // And how can that list_add() in the "else" clause
@@ -1063,12 +1064,12 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
                // can only be executed during early boot when there is only
                // the one boot CPU running with interrupts still disabled.
                if (likely(srcu_init_done))
-                       queue_delayed_work(rcu_gp_wq, &ssp->srcu_sup->work,
+                       queue_delayed_work(rcu_gp_wq, &sup->work,
                                           !!srcu_get_delay(ssp));
-               else if (list_empty(&ssp->srcu_sup->work.work.entry))
-                       list_add(&ssp->srcu_sup->work.work.entry, &srcu_boot_list);
+               else if (list_empty(&sup->work.work.entry))
+                       list_add(&sup->work.work.entry, &srcu_boot_list);
        }
-       spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+       spin_unlock_irqrestore_rcu_node(sup, flags);
 }
 
 /*