On Thu, Jan 5, 2023 at 4:43 AM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
>
> On Fri, Dec 23, 2022 at 09:02:28PM +0800, Pingfan Liu wrote:
> > Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
> > Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
> > Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
> > Cc: Frederic Weisbecker <frederic@xxxxxxxxxx>,
> > Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> > Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> > Cc: "Zhang, Qiang1" <qiang1.zhang@xxxxxxxxx>
> > To: rcu@xxxxxxxxxxxxxxx
>
> Queued, thank you!
>
> After the inevitable wordsmithing, it appears as follows. Could you
Sorry for the poor English expression.
> please check it? (And yes, it does take advantage of 100 columns.)
>
It looks better to me.
Thanks,
Pingfan
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit 9c473f0ef9eb8f3ac76d8295cfb4065a738b07a1
> Author: Pingfan Liu <kernelfans@xxxxxxxxx>
> Date: Wed Jan 4 12:29:01 2023 -0800
>
> srcu: Add comments for srcu_size_state
>
> The SRCU_SIZE_* names are not self-explanatory, so this commit therefore
> adds comments to the definitions.
>
> Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
> Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
> Cc: Frederic Weisbecker <frederic@xxxxxxxxxx>,
> Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> Cc: "Zhang, Qiang1" <qiang1.zhang@xxxxxxxxx>
> To: rcu@xxxxxxxxxxxxxxx
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
>
> diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h
> index 558057b517b74..a6910805f9c51 100644
> --- a/include/linux/srcutree.h
> +++ b/include/linux/srcutree.h
> @@ -92,16 +92,29 @@ struct srcu_struct {
> struct lockdep_map dep_map;
> };
>
> -/* Values for size state variable (->srcu_size_state). */
> -#define SRCU_SIZE_SMALL 0
> -#define SRCU_SIZE_ALLOC 1
> -#define SRCU_SIZE_WAIT_BARRIER 2
> -#define SRCU_SIZE_WAIT_CALL 3
> -#define SRCU_SIZE_WAIT_CBS1 4
> -#define SRCU_SIZE_WAIT_CBS2 5
> -#define SRCU_SIZE_WAIT_CBS3 6
> -#define SRCU_SIZE_WAIT_CBS4 7
> -#define SRCU_SIZE_BIG 8
> +// Values for size state variable (->srcu_size_state). Once the state
> +// has been set to SRCU_SIZE_ALLOC, the grace-period code advances through
> +// this state machine one step per grace period until the SRCU_SIZE_BIG state
> +// is reached. Otherwise, the state machine remains in the SRCU_SIZE_SMALL
> +// state indefinitely.
> +#define SRCU_SIZE_SMALL 0 // No srcu_node combining tree, ->node == NULL
> +#define SRCU_SIZE_ALLOC 1 // An srcu_node tree is being allocated, initialized,
> + // and then referenced by ->node. It will not be used.
> +#define SRCU_SIZE_WAIT_BARRIER 2 // The srcu_node tree starts being used by everything
> + // except call_srcu(), especially by srcu_barrier().
> + // By the end of this state, all CPUs and threads
> + // are aware of this tree's existence.
> +#define SRCU_SIZE_WAIT_CALL 3 // The srcu_node tree starts being used by call_srcu().
> + // By the end of this state, all of the call_srcu()
> + // invocations that were running on a non-boot CPU
> + // and using the boot CPU's callback queue will have
> + // completed.
> +#define SRCU_SIZE_WAIT_CBS1 4 // Don't trust the ->srcu_have_cbs[] grace-period
> +#define SRCU_SIZE_WAIT_CBS2 5 // sequence elements or the ->srcu_data_have_cbs[]
> +#define SRCU_SIZE_WAIT_CBS3 6 // CPU-bitmask elements until all four elements of
> +#define SRCU_SIZE_WAIT_CBS4 7 // each array have been initialized.
> +#define SRCU_SIZE_BIG 8 // The srcu_node combining tree is fully initialized
> + // and all aspects of it are being put to use.
>
> /* Values for state variable (bottom bits of ->srcu_gp_seq). */
> #define SRCU_STATE_IDLE 0
