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| author |   Lai Jiangshan <laijs@linux.alibaba.com> | 2019-11-01 05:06:21 -0700 |
|---|---|---|
| committer |   Paul E. McKenney <paulmck@kernel.org> | 2020-01-24 10:27:33 -0800 |
| commit | 3717e1e9f25ec7059e421ab6fc602cab7063c11c (patch) | |
| tree | e3be4d9999576967141e14a0ade78330474d36e1 /kernel | |
| parent | rcu: Clear .exp_hint only when deferred quiescent state has been reported (diff) | |
| download | linux-dev-3717e1e9f25ec7059e421ab6fc602cab7063c11c.tar.xz linux-dev-3717e1e9f25ec7059e421ab6fc602cab7063c11c.zip | |
rcu: Clear ->rcu_read_unlock_special only once
In rcu_preempt_deferred_qs_irqrestore(), ->rcu_read_unlock_special is
cleared one piece at a time. Given that the "if" statements in this
function use the copy in "special", this commit removes the clearing
of the individual pieces in favor of clearing ->rcu_read_unlock_special
in one go just after it has been determined to be non-zero.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 19 |
1 files changed, 3 insertions, 16 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 7487c7930a47..c3a32717c42d 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -444,16 +444,9 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) local_irq_restore(flags); return; } - t->rcu_read_unlock_special.b.exp_hint = false; - t->rcu_read_unlock_special.b.deferred_qs = false; - if (special.b.need_qs) { + t->rcu_read_unlock_special.s = 0; + if (special.b.need_qs) rcu_qs(); - t->rcu_read_unlock_special.b.need_qs = false; - if (!t->rcu_read_unlock_special.s && !rdp->exp_deferred_qs) { - local_irq_restore(flags); - return; - } - } /* * Respond to a request by an expedited grace period for a @@ -461,17 +454,11 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) * tasks are handled when removing the task from the * blocked-tasks list below. */ - if (rdp->exp_deferred_qs) { + if (rdp->exp_deferred_qs) rcu_report_exp_rdp(rdp); - if (!t->rcu_read_unlock_special.s) { - local_irq_restore(flags); - return; - } - } /* Clean up if blocked during RCU read-side critical section. */ if (special.b.blocked) { - t->rcu_read_unlock_special.b.blocked = false; /* * Remove this task from the list it blocked on. The task |