Messages in this thread Patch in this message | | | From | paulmck@kernel ... | Subject | [PATCH tip/core/rcu 20/24] rcu: Clarify comments about FQS loop reporting quiescent states | Date | Mon, 31 Aug 2020 11:01:12 -0700 |
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From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Since at least v4.19, the FQS loop no longer reports quiescent states for offline CPUs except in emergency situations.
This commit therefore fixes the comment in rcu_gp_init() to match the current code.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- kernel/rcu/tree.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 52108dd..2c7afe4 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1706,10 +1706,13 @@ static bool rcu_gp_init(void) raw_spin_unlock_irq_rcu_node(rnp); /* - * Apply per-leaf buffered online and offline operations to the - * rcu_node tree. Note that this new grace period need not wait - * for subsequent online CPUs, and that quiescent-state forcing - * will handle subsequent offline CPUs. + * Apply per-leaf buffered online and offline operations to + * the rcu_node tree. Note that this new grace period need not + * wait for subsequent online CPUs, and that RCU hooks in the CPU + * offlining path, when combined with checks in this function, + * will handle CPUs that are currently going offline or that will + * go offline later. Please also refer to "Hotplug CPU" section + * of RCU's Requirements documentation. */ rcu_state.gp_state = RCU_GP_ONOFF; rcu_for_each_leaf_node(rnp) { -- 2.9.5
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