srcu: Fix long lines in srcu_gp_end()

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 11a08201ca0ab211d8c17600676fb870a9df9bf4..f661a0f6bc0dbd60ed00077b57a7da805fcece70 100644 (file)
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -862,28 +862,29 @@ static void srcu_gp_end(struct srcu_struct *ssp)
        unsigned long sgsne;
        struct srcu_node *snp;
        int ss_state;
+       struct srcu_usage *sup = ssp->srcu_sup;
 
        /* Prevent more than one additional grace period. */
-       mutex_lock(&ssp->srcu_sup->srcu_cb_mutex);
+       mutex_lock(&sup->srcu_cb_mutex);
 
        /* End the current grace period. */
-       spin_lock_irq_rcu_node(ssp->srcu_sup);
-       idx = rcu_seq_state(ssp->srcu_sup->srcu_gp_seq);
+       spin_lock_irq_rcu_node(sup);
+       idx = rcu_seq_state(sup->srcu_gp_seq);
        WARN_ON_ONCE(idx != SRCU_STATE_SCAN2);
-       if (ULONG_CMP_LT(READ_ONCE(ssp->srcu_sup->srcu_gp_seq), READ_ONCE(ssp->srcu_sup->srcu_gp_seq_needed_exp)))
+       if (ULONG_CMP_LT(READ_ONCE(sup->srcu_gp_seq), READ_ONCE(sup->srcu_gp_seq_needed_exp)))
                cbdelay = 0;
 
-       WRITE_ONCE(ssp->srcu_sup->srcu_last_gp_end, ktime_get_mono_fast_ns());
-       rcu_seq_end(&ssp->srcu_sup->srcu_gp_seq);
-       gpseq = rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq);
-       if (ULONG_CMP_LT(ssp->srcu_sup->srcu_gp_seq_needed_exp, gpseq))
-               WRITE_ONCE(ssp->srcu_sup->srcu_gp_seq_needed_exp, gpseq);
-       spin_unlock_irq_rcu_node(ssp->srcu_sup);
-       mutex_unlock(&ssp->srcu_sup->srcu_gp_mutex);
+       WRITE_ONCE(sup->srcu_last_gp_end, ktime_get_mono_fast_ns());
+       rcu_seq_end(&sup->srcu_gp_seq);
+       gpseq = rcu_seq_current(&sup->srcu_gp_seq);
+       if (ULONG_CMP_LT(sup->srcu_gp_seq_needed_exp, gpseq))
+               WRITE_ONCE(sup->srcu_gp_seq_needed_exp, gpseq);
+       spin_unlock_irq_rcu_node(sup);
+       mutex_unlock(&sup->srcu_gp_mutex);
        /* A new grace period can start at this point.  But only one. */
 
        /* Initiate callback invocation as needed. */
-       ss_state = smp_load_acquire(&ssp->srcu_sup->srcu_size_state);
+       ss_state = smp_load_acquire(&sup->srcu_size_state);
        if (ss_state < SRCU_SIZE_WAIT_BARRIER) {
                srcu_schedule_cbs_sdp(per_cpu_ptr(ssp->sda, get_boot_cpu_id()),
                                        cbdelay);
@@ -892,7 +893,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
                srcu_for_each_node_breadth_first(ssp, snp) {
                        spin_lock_irq_rcu_node(snp);
                        cbs = false;
-                       last_lvl = snp >= ssp->srcu_sup->level[rcu_num_lvls - 1];
+                       last_lvl = snp >= sup->level[rcu_num_lvls - 1];
                        if (last_lvl)
                                cbs = ss_state < SRCU_SIZE_BIG || snp->srcu_have_cbs[idx] == gpseq;
                        snp->srcu_have_cbs[idx] = gpseq;
@@ -924,18 +925,18 @@ static void srcu_gp_end(struct srcu_struct *ssp)
                }
 
        /* Callback initiation done, allow grace periods after next. */
-       mutex_unlock(&ssp->srcu_sup->srcu_cb_mutex);
+       mutex_unlock(&sup->srcu_cb_mutex);
 
        /* Start a new grace period if needed. */
-       spin_lock_irq_rcu_node(ssp->srcu_sup);
-       gpseq = rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq);
+       spin_lock_irq_rcu_node(sup);
+       gpseq = rcu_seq_current(&sup->srcu_gp_seq);
        if (!rcu_seq_state(gpseq) &&
-           ULONG_CMP_LT(gpseq, ssp->srcu_sup->srcu_gp_seq_needed)) {
+           ULONG_CMP_LT(gpseq, sup->srcu_gp_seq_needed)) {
                srcu_gp_start(ssp);
-               spin_unlock_irq_rcu_node(ssp->srcu_sup);
+               spin_unlock_irq_rcu_node(sup);
                srcu_reschedule(ssp, 0);
        } else {
-               spin_unlock_irq_rcu_node(ssp->srcu_sup);
+               spin_unlock_irq_rcu_node(sup);
        }
 
        /* Transition to big if needed. */
@@ -943,7 +944,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
                if (ss_state == SRCU_SIZE_ALLOC)
                        init_srcu_struct_nodes(ssp, GFP_KERNEL);
                else
-                       smp_store_release(&ssp->srcu_sup->srcu_size_state, ss_state + 1);
+                       smp_store_release(&sup->srcu_size_state, ss_state + 1);
        }
 }