Commit cefc0a59 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

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: default avatarSachin Sant <sachinp@linux.ibm.com>
Tested-by: default avatar"Zhang, Qiang1" <qiang1.zhang@intel.com>
Tested-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 6c366522

kernel/rcu/srcutree.c

+14 −13
Original line number Diff line number Diff line
@@ -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);

}



/*