From 27153acbe1141ceecf098ca5d24c2ae2714c1a5f Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Wed, 11 Feb 2015 15:42:37 +0100 Subject: rcu: Remove unnecessary condition check in rcu_qsctr_help() When the ->curtail and ->donetail pointers differ, ->rcucblist always points to the beginning of the current list and thus cannot be NULL. Therefore, the check ->rcucblist != NULL is redundant and this commit removes it. Cc: "Paul E. McKenney" Signed-off-by: Alexander Gordeev Signed-off-by: Paul E. McKenney --- kernel/rcu/tiny.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/rcu/tiny.c') diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index cc9ceca7bde1..d4e7fe5f3baf 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -103,8 +103,7 @@ EXPORT_SYMBOL(__rcu_is_watching); static int rcu_qsctr_help(struct rcu_ctrlblk *rcp) { RCU_TRACE(reset_cpu_stall_ticks(rcp)); - if (rcp->rcucblist != NULL && - rcp->donetail != rcp->curtail) { + if (rcp->donetail != rcp->curtail) { rcp->donetail = rcp->curtail; return 1; } -- cgit v1.2.3 From 915e8a4fe45eab871a862f6467ec7e59864735b2 Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Wed, 11 Feb 2015 15:42:38 +0100 Subject: rcu: Remove fastpath from __rcu_process_callbacks() The standard code path accommodates a condition when no RCU callbacks are ready to invoke. Since size of the code is a priority for tiny RCU, remove the fast path. Cc: "Paul E. McKenney" Signed-off-by: Alexander Gordeev Signed-off-by: Paul E. McKenney --- kernel/rcu/tiny.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'kernel/rcu/tiny.c') diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index d4e7fe5f3baf..069742d61c68 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -168,17 +168,6 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp) unsigned long flags; RCU_TRACE(int cb_count = 0); - /* If no RCU callbacks ready to invoke, just return. */ - if (&rcp->rcucblist == rcp->donetail) { - RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, 0, -1)); - RCU_TRACE(trace_rcu_batch_end(rcp->name, 0, - !!ACCESS_ONCE(rcp->rcucblist), - need_resched(), - is_idle_task(current), - false)); - return; - } - /* Move the ready-to-invoke callbacks to a local list. */ local_irq_save(flags); RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1)); -- cgit v1.2.3