From dcdb8807ba0f5127d4dc67daeeb154edf50a93d1 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 15 Aug 2015 19:00:31 -0700 Subject: rcu: Consolidate expedited CPU selection Now that sync_sched_exp_select_cpus() and sync_rcu_exp_select_cpus() are identical aside from the the argument to smp_call_function_single(), this commit consolidates them with a functional argument. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 7 +++--- kernel/rcu/tree_plugin.h | 61 +----------------------------------------------- 2 files changed, 5 insertions(+), 63 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index ae582e3d4136..f44f4b30c68a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3654,7 +3654,8 @@ static void synchronize_sched_expedited_cpu_stop(void *data) * Select the nodes that the upcoming expedited grace period needs * to wait for. */ -static void sync_sched_exp_select_cpus(struct rcu_state *rsp) +static void sync_rcu_exp_select_cpus(struct rcu_state *rsp, + smp_call_func_t func) { int cpu; unsigned long flags; @@ -3696,7 +3697,7 @@ static void sync_sched_exp_select_cpus(struct rcu_state *rsp) for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) { if (!(mask_ofl_ipi & mask)) continue; - ret = smp_call_function_single(cpu, synchronize_sched_expedited_cpu_stop, NULL, 0); + ret = smp_call_function_single(cpu, func, rsp, 0); if (!ret) mask_ofl_ipi &= ~mask; } @@ -3788,7 +3789,7 @@ void synchronize_sched_expedited(void) return; /* Someone else did our work for us. */ rcu_exp_gp_seq_start(rsp); - sync_sched_exp_select_cpus(rsp); + sync_rcu_exp_select_cpus(rsp, synchronize_sched_expedited_cpu_stop); synchronize_sched_expedited_wait(rsp); rcu_exp_gp_seq_end(rsp); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 7880202f1e38..6cbfbfc58656 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -708,65 +708,6 @@ static void sync_rcu_exp_handler(void *info) rcu_report_exp_rdp(rsp, rdp, true); } -/* - * Select the nodes that the upcoming expedited grace period needs - * to wait for. - */ -static void sync_rcu_exp_select_cpus(struct rcu_state *rsp) -{ - int cpu; - unsigned long flags; - unsigned long mask; - unsigned long mask_ofl_test; - unsigned long mask_ofl_ipi; - int ret; - struct rcu_node *rnp; - - sync_exp_reset_tree(rsp); - rcu_for_each_leaf_node(rsp, rnp) { - raw_spin_lock_irqsave(&rnp->lock, flags); - smp_mb__after_unlock_lock(); - - /* Each pass checks a CPU for identity, offline, and idle. */ - mask_ofl_test = 0; - for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++) { - struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); - struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); - - if (raw_smp_processor_id() == cpu || - cpu_is_offline(cpu) || - !(atomic_add_return(0, &rdtp->dynticks) & 0x1)) - mask_ofl_test |= rdp->grpmask; - } - mask_ofl_ipi = rnp->expmask & ~mask_ofl_test; - - /* - * Need to wait for any blocked tasks as well. Note that - * additional blocking tasks will also block the expedited - * GP until such time as the ->expmask bits are cleared. - */ - if (rcu_preempt_has_tasks(rnp)) - rnp->exp_tasks = rnp->blkd_tasks.next; - raw_spin_unlock_irqrestore(&rnp->lock, flags); - - /* IPI the remaining CPUs for expedited quiescent state. */ - mask = 1; - for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) { - if (!(mask_ofl_ipi & mask)) - continue; - ret = smp_call_function_single(cpu, - sync_rcu_exp_handler, - rsp, 0); - if (!ret) - mask_ofl_ipi &= ~mask; - } - /* Report quiescent states for those that went offline. */ - mask_ofl_test |= mask_ofl_ipi; - if (mask_ofl_test) - rcu_report_exp_cpu_mult(rsp, rnp, mask_ofl_test, false); - } -} - /** * synchronize_rcu_expedited - Brute-force RCU grace period * @@ -795,7 +736,7 @@ void synchronize_rcu_expedited(void) rcu_exp_gp_seq_start(rsp); /* Initialize the rcu_node tree in preparation for the wait. */ - sync_rcu_exp_select_cpus(rsp); + sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler); /* Wait for snapshotted ->blkd_tasks lists to drain. */ rnp = rcu_get_root(rsp); -- cgit v1.2.3