diff options
| -rw-r--r-- | include/linux/srcutree.h | 4 | ||||
| -rw-r--r-- | kernel/rcu/srcutree.c | 29 |
2 files changed, 27 insertions, 6 deletions
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 0400e211aa44..94515ff226fb 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -47,6 +47,8 @@ struct srcu_data { struct delayed_work work; /* Context for CB invoking. */ struct rcu_head srcu_barrier_head; /* For srcu_barrier() use. */ struct srcu_node *mynode; /* Leaf srcu_node. */ + unsigned long grpmask; /* Mask for leaf srcu_node */ + /* ->srcu_data_have_cbs[]. */ int cpu; struct srcu_struct *sp; }; @@ -59,6 +61,8 @@ struct srcu_node { unsigned long srcu_have_cbs[4]; /* GP seq for children */ /* having CBs, but only */ /* is > ->srcu_gq_seq. */ + unsigned long srcu_data_have_cbs[4]; /* Which srcu_data structs */ + /* have CBs for given GP? */ struct srcu_node *srcu_parent; /* Next up in tree. */ int grplo; /* Least CPU for node. */ int grphi; /* Biggest CPU for node. */ diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 9ecf0acc18eb..1c2c1004b3b1 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -66,8 +66,12 @@ static void init_srcu_struct_nodes(struct srcu_struct *sp, bool is_static) /* Each pass through this loop initializes one srcu_node structure. */ rcu_for_each_node_breadth_first(sp, snp) { spin_lock_init(&snp->lock); - for (i = 0; i < ARRAY_SIZE(snp->srcu_have_cbs); i++) + WARN_ON_ONCE(ARRAY_SIZE(snp->srcu_have_cbs) != + ARRAY_SIZE(snp->srcu_data_have_cbs)); + for (i = 0; i < ARRAY_SIZE(snp->srcu_have_cbs); i++) { snp->srcu_have_cbs[i] = 0; + snp->srcu_data_have_cbs[i] = 0; + } snp->grplo = -1; snp->grphi = -1; if (snp == &sp->node[0]) { @@ -107,6 +111,7 @@ static void init_srcu_struct_nodes(struct srcu_struct *sp, bool is_static) sdp->cpu = cpu; INIT_DELAYED_WORK(&sdp->work, srcu_invoke_callbacks); sdp->sp = sp; + sdp->grpmask = 1 << (cpu - sdp->mynode->grplo); if (is_static) continue; @@ -434,16 +439,21 @@ static void srcu_schedule_cbs_sdp(struct srcu_data *sdp, unsigned long delay) /* * Schedule callback invocation for all srcu_data structures associated - * with the specified srcu_node structure, if possible, on the corresponding - * CPUs. + * with the specified srcu_node structure that have callbacks for the + * just-completed grace period, the one corresponding to idx. If possible, + * schedule this invocation on the corresponding CPUs. */ -static void srcu_schedule_cbs_snp(struct srcu_struct *sp, struct srcu_node *snp) +static void srcu_schedule_cbs_snp(struct srcu_struct *sp, struct srcu_node *snp, + unsigned long mask) { int cpu; - for (cpu = snp->grplo; cpu <= snp->grphi; cpu++) + for (cpu = snp->grplo; cpu <= snp->grphi; cpu++) { + if (!(mask & (1 << (cpu - snp->grplo)))) + continue; srcu_schedule_cbs_sdp(per_cpu_ptr(sp->sda, cpu), atomic_read(&sp->srcu_exp_cnt) ? 0 : SRCU_INTERVAL); + } } /* @@ -461,6 +471,7 @@ static void srcu_gp_end(struct srcu_struct *sp) unsigned long gpseq; int idx; int idxnext; + unsigned long mask; struct srcu_node *snp; /* Prevent more than one additional grace period. */ @@ -486,10 +497,12 @@ static void srcu_gp_end(struct srcu_struct *sp) cbs = snp->srcu_have_cbs[idx] == gpseq; snp->srcu_have_cbs[idx] = gpseq; rcu_seq_set_state(&snp->srcu_have_cbs[idx], 1); + mask = snp->srcu_data_have_cbs[idx]; + snp->srcu_data_have_cbs[idx] = 0; spin_unlock_irq(&snp->lock); if (cbs) { smp_mb(); /* GP end before CB invocation. */ - srcu_schedule_cbs_snp(sp, snp); + srcu_schedule_cbs_snp(sp, snp, mask); } } @@ -536,6 +549,8 @@ static void srcu_funnel_gp_start(struct srcu_struct *sp, spin_lock_irqsave(&snp->lock, flags); if (ULONG_CMP_GE(snp->srcu_have_cbs[idx], s)) { snp_seq = snp->srcu_have_cbs[idx]; + if (snp == sdp->mynode && snp_seq == s) + snp->srcu_data_have_cbs[idx] |= sdp->grpmask; spin_unlock_irqrestore(&snp->lock, flags); if (snp == sdp->mynode && snp_seq != s) { smp_mb(); /* CBs after GP! */ @@ -544,6 +559,8 @@ static void srcu_funnel_gp_start(struct srcu_struct *sp, return; } snp->srcu_have_cbs[idx] = s; + if (snp == sdp->mynode) + snp->srcu_data_have_cbs[idx] |= sdp->grpmask; spin_unlock_irqrestore(&snp->lock, flags); } |