Re: [PATCH RFC 2/3] rcu: tree: Fix comment about gp_seq_needed
From: Paul E. McKenney
Date: Sat Sep 22 2018 - 20:37:04 EST
On Sat, Sep 22, 2018 at 07:41:26PM -0400, Joel Fernandes (Google) wrote:
> rcu_state does not have a gp_seq_needed field. This comment therefore is
> confusing or incorrect. Fix it.
>
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Good eyes, queued and pushed with edits, thank you!
(Yes, I do have a great deal of experience with punched cards. Why do
you ask?)
Thanx, Paul
> ---
> kernel/rcu/tree.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> index 57a937ac51c2..fd2ba3f9eee9 100644
> --- a/kernel/rcu/tree.h
> +++ b/kernel/rcu/tree.h
> @@ -57,7 +57,7 @@ struct rcu_node {
> /* some rcu_state fields as well as */
> /* following. */
> unsigned long gp_seq; /* Track rsp->rcu_gp_seq. */
> - unsigned long gp_seq_needed; /* Track rsp->rcu_gp_seq_needed. */
> + unsigned long gp_seq_needed; /* Track the furthest future gp request seen */
> unsigned long completedqs; /* All QSes done for this node. */
> unsigned long qsmask; /* CPUs or groups that need to switch in */
> /* order for current grace period to proceed.*/
> @@ -163,7 +163,7 @@ union rcu_noqs {
> struct rcu_data {
> /* 1) quiescent-state and grace-period handling : */
> unsigned long gp_seq; /* Track rsp->rcu_gp_seq counter. */
> - unsigned long gp_seq_needed; /* Track rsp->rcu_gp_seq_needed ctr. */
> + unsigned long gp_seq_needed; /* Track the furthest future gp request seen */
> union rcu_noqs cpu_no_qs; /* No QSes yet for this CPU. */
> bool core_needs_qs; /* Core waits for quiesc state. */
> bool beenonline; /* CPU online at least once. */
> --
> 2.19.0.444.g18242da7ef-goog
>