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rcu: Eliminate initialization-time use of rsp

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Now that there is only one rcu_state structure, there is less point in
maintaining a pointer to it.  This commit therefore replaces rsp with
&rcu_state in rcu_cpu_starting() and rcu_init_one().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2018-07-05 17:47:45 -07:00
parent ec9f5835f7
commit eb7a665388
1 changed files with 12 additions and 13 deletions
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25
kernel/rcu/tree.c
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@ -3455,7 +3455,6 @@ void rcu_cpu_starting(unsigned int cpu)
unsigned long oldmask;
struct rcu_data *rdp;
struct rcu_node *rnp;
struct rcu_state *rsp = &rcu_state;
if (per_cpu(rcu_cpu_started, cpu))
return;
@ -3472,10 +3471,10 @@ void rcu_cpu_starting(unsigned int cpu)
oldmask ^= rnp->expmaskinitnext;
nbits = bitmap_weight(&oldmask, BITS_PER_LONG);
/* Allow lockless access for expedited grace periods. */
smp_store_release(&rsp->ncpus, rsp->ncpus + nbits); /* ^^^ */
smp_store_release(&rcu_state.ncpus, rcu_state.ncpus + nbits); /* ^^^ */
rcu_gpnum_ovf(rnp, rdp); /* Offline-induced counter wrap? */
rdp->rcu_onl_gp_seq = READ_ONCE(rsp->gp_seq);
rdp->rcu_onl_gp_flags = READ_ONCE(rsp->gp_flags);
rdp->rcu_onl_gp_seq = READ_ONCE(rcu_state.gp_seq);
rdp->rcu_onl_gp_flags = READ_ONCE(rcu_state.gp_flags);
if (rnp->qsmask & mask) { /* RCU waiting on incoming CPU? */
/* Report QS -after- changing ->qsmaskinitnext! */
rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
@ -3667,7 +3666,6 @@ static void __init rcu_init_one(void)
int i;
int j;
struct rcu_node *rnp;
struct rcu_state *rsp = &rcu_state;
BUILD_BUG_ON(RCU_NUM_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */
@ -3678,14 +3676,15 @@ static void __init rcu_init_one(void)
/* Initialize the level-tracking arrays. */
for (i = 1; i < rcu_num_lvls; i++)
rsp->level[i] = rsp->level[i - 1] + num_rcu_lvl[i - 1];
rcu_state.level[i] =
rcu_state.level[i - 1] + num_rcu_lvl[i - 1];
rcu_init_levelspread(levelspread, num_rcu_lvl);
/* Initialize the elements themselves, starting from the leaves. */
for (i = rcu_num_lvls - 1; i >= 0; i--) {
cpustride *= levelspread[i];
rnp = rsp->level[i];
rnp = rcu_state.level[i];
for (j = 0; j < num_rcu_lvl[i]; j++, rnp++) {
raw_spin_lock_init(&ACCESS_PRIVATE(rnp, lock));
lockdep_set_class_and_name(&ACCESS_PRIVATE(rnp, lock),
@ -3693,9 +3692,9 @@ static void __init rcu_init_one(void)
raw_spin_lock_init(&rnp->fqslock);
lockdep_set_class_and_name(&rnp->fqslock,
&rcu_fqs_class[i], fqs[i]);
rnp->gp_seq = rsp->gp_seq;
rnp->gp_seq_needed = rsp->gp_seq;
rnp->completedqs = rsp->gp_seq;
rnp->gp_seq = rcu_state.gp_seq;
rnp->gp_seq_needed = rcu_state.gp_seq;
rnp->completedqs = rcu_state.gp_seq;
rnp->qsmask = 0;
rnp->qsmaskinit = 0;
rnp->grplo = j * cpustride;
@ -3709,7 +3708,7 @@ static void __init rcu_init_one(void)
} else {
rnp->grpnum = j % levelspread[i - 1];
rnp->grpmask = 1UL << rnp->grpnum;
rnp->parent = rsp->level[i - 1] +
rnp->parent = rcu_state.level[i - 1] +
j / levelspread[i - 1];
}
rnp->level = i;
@ -3723,8 +3722,8 @@ static void __init rcu_init_one(void)
}
}
init_swait_queue_head(&rsp->gp_wq);
init_swait_queue_head(&rsp->expedited_wq);
init_swait_queue_head(&rcu_state.gp_wq);
init_swait_queue_head(&rcu_state.expedited_wq);
rnp = rcu_first_leaf_node();
for_each_possible_cpu(i) {
while (i > rnp->grphi)