45 lines
1.7 KiB
Diff
45 lines
1.7 KiB
Diff
From: Paul E. McKenney <paulmck@linux.ibm.com>
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Date: Mon, 29 Oct 2018 11:53:01 +0100
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Subject: [PATCH] EXP rcu: Revert expedited GP parallelization cleverness
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.1-rt3.tar.xz
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(Commit 258ba8e089db23f760139266c232f01bad73f85c from linux-rcu)
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This commit reverts a series of commits starting with fcc635436501 ("rcu:
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Make expedited GPs handle CPU 0 being offline") and its successors, thus
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queueing each rcu_node structure's expedited grace-period initialization
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work on the first CPU of that rcu_node structure.
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Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/rcu/tree_exp.h | 9 +--------
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1 file changed, 1 insertion(+), 8 deletions(-)
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--- a/kernel/rcu/tree_exp.h
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+++ b/kernel/rcu/tree_exp.h
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@@ -472,7 +472,6 @@ static void sync_rcu_exp_select_node_cpu
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static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
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smp_call_func_t func)
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{
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- int cpu;
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struct rcu_node *rnp;
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trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("reset"));
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@@ -494,13 +493,7 @@ static void sync_rcu_exp_select_cpus(str
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continue;
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}
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INIT_WORK(&rnp->rew.rew_work, sync_rcu_exp_select_node_cpus);
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- preempt_disable();
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- cpu = cpumask_next(rnp->grplo - 1, cpu_online_mask);
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- /* If all offline, queue the work on an unbound CPU. */
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- if (unlikely(cpu > rnp->grphi))
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- cpu = WORK_CPU_UNBOUND;
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- queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work);
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- preempt_enable();
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+ queue_work_on(rnp->grplo, rcu_par_gp_wq, &rnp->rew.rew_work);
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rnp->exp_need_flush = true;
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}
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