Messages in this thread Patch in this message | | | From | "Joel Fernandes (Google)" <> | Subject | [PATCH v4 2/5] rcu/tree: Clarify comments about FQS loop reporting quiescent states | Date | Fri, 7 Aug 2020 13:07:19 -0400 |
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At least since v4.19, the FQS loop no longer reports quiescent states for offline CPUs unless it is an emergency.
This commit therefore fixes the comment in rcu_gp_init() to match the current code.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- kernel/rcu/tree.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a49fa3b60faa..2fb66cdbfa25 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1701,9 +1701,11 @@ static bool rcu_gp_init(void) /* * 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. + * 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 go offline later. Refer to + * RCU's Requirements documentation about hotplug requirements as well. */ rcu_state.gp_state = RCU_GP_ONOFF; rcu_for_each_leaf_node(rnp) { -- 2.28.0.236.gb10cc79966-goog
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