Messages in this thread Patch in this message | | | From | Boqun Feng <> | Subject | [RFC 4/5] rcu: Use leaf_node_for_each_mask_possible_cpu() in force_qs_rnp() | Date | Fri, 9 Dec 2016 16:48:26 +0800 |
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->qsmask of an RCU leaf node is usually more sparse than the corresponding cpu_possible_mask. So replace the for_each_leaf_node_possible_cpu() in force_qs_rnp() with leaf_node_for_each_mask_possible_cpu() to save several checks.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com> --- kernel/rcu/tree.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 5f6802b9ba5f..10162ac71dbe 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3014,6 +3014,7 @@ static void force_qs_rnp(struct rcu_state *rsp, bool *isidle, unsigned long *maxj) { int cpu; + unsigned long bit; unsigned long flags; unsigned long mask; struct rcu_node *rnp; @@ -3047,13 +3048,11 @@ static void force_qs_rnp(struct rcu_state *rsp, continue; } } - for_each_leaf_node_possible_cpu(rnp, cpu) { - unsigned long bit = leaf_node_cpu_bit(rnp, cpu); - if ((rnp->qsmask & bit) != 0) { - if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj)) - mask |= bit; - } - } + + leaf_node_for_each_mask_possible_cpu(rnp, rnp->qsmask, bit, cpu) + if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj)) + mask |= 1 << bit; + if (mask != 0) { /* Idle/offline CPUs, report (releases rnp->lock. */ rcu_report_qs_rnp(mask, rsp, rnp, rnp->gpnum, flags); -- 2.10.2
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