Commit 7ecef087 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Remove ->rgos_polled field from rcu_gp_oldstate structure 



Because both normal and expedited grace periods increment their respective
counters on their pre-scheduler early boot fastpaths, the rcu_gp_oldstate
structure no longer needs its ->rgos_polled field.  This commit therefore
removes this field, shrinking this structure so that it is the same size
as an rcu_head structure.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 43ff97cc

include/linux/rcutree.h

+0 −1
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ bool rcu_gp_might_be_stalled(void); 
struct rcu_gp_oldstate {

	unsigned long rgos_norm;

	unsigned long rgos_exp;

	unsigned long rgos_polled;

};



unsigned long start_poll_synchronize_rcu_expedited(void);

kernel/rcu/tree.c

+1 −5
Original line number Diff line number Diff line
@@ -3526,7 +3526,6 @@ void get_completed_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) 
{

	rgosp->rgos_norm = RCU_GET_STATE_COMPLETED;

	rgosp->rgos_exp = RCU_GET_STATE_COMPLETED;

	rgosp->rgos_polled = RCU_GET_STATE_COMPLETED;

}

EXPORT_SYMBOL_GPL(get_completed_synchronize_rcu_full);
@@ -3575,7 +3574,6 @@ void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) 
	smp_mb();  /* ^^^ */

	rgosp->rgos_norm = rcu_seq_snap(&rnp->gp_seq);

	rgosp->rgos_exp = rcu_seq_snap(&rcu_state.expedited_sequence);

	rgosp->rgos_polled = rcu_seq_snap(&rcu_state.gp_seq_polled);

}

EXPORT_SYMBOL_GPL(get_state_synchronize_rcu_full);
@@ -3727,9 +3725,7 @@ bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) 
	if (rgosp->rgos_norm == RCU_GET_STATE_COMPLETED ||

	    rcu_seq_done_exact(&rnp->gp_seq, rgosp->rgos_norm) ||

	    rgosp->rgos_exp == RCU_GET_STATE_COMPLETED ||

	    rcu_seq_done_exact(&rcu_state.expedited_sequence, rgosp->rgos_exp) ||

	    rgosp->rgos_polled == RCU_GET_STATE_COMPLETED ||

	    rcu_seq_done_exact(&rcu_state.gp_seq_polled, rgosp->rgos_polled)) {

	    rcu_seq_done_exact(&rcu_state.expedited_sequence, rgosp->rgos_exp)) {

		smp_mb(); /* Ensure GP ends before subsequent accesses. */

		return true;

	}