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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-04-13 17:46:15 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-07-21 17:40:06 -0700 |
| commit | bf95b2bc3e42f11f4d7a5e8a98376c2b4a2aa82f (patch) | |
| tree | 3ce1e41e99ac8a626380683b43391b4bf0b45693 /kernel/rcu/tree.h | |
| parent | d0eac20f9909de044fbeb958960b08ff235cf8a2 (diff) | |
| download | linux-bf95b2bc3e42f11f4d7a5e8a98376c2b4a2aa82f.tar.gz | |
rcu: Switch polled grace-period APIs to ->gp_seq_polled
This commit switches the existing polled grace-period APIs to use a
new ->gp_seq_polled counter in the rcu_state structure. An additional
->gp_seq_polled_snap counter in that same structure allows the normal
grace period kthread to interact properly with the !SMP !PREEMPT fastpath
through synchronize_rcu(). The first of the two to note the end of a
given grace period will make knowledge of this transition available to
the polled API.
This commit is in preparation for polled expedited grace periods.
[ paulmck: Fix use of rcu_state.gp_seq_polled to start normal grace period. ]
Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 2ccf5845957d..9c853033f159 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -323,6 +323,8 @@ struct rcu_state { short gp_state; /* GP kthread sleep state. */ unsigned long gp_wake_time; /* Last GP kthread wake. */ unsigned long gp_wake_seq; /* ->gp_seq at ^^^. */ + unsigned long gp_seq_polled; /* GP seq for polled API. */ + unsigned long gp_seq_polled_snap; /* ->gp_seq_polled at normal GP start. */ /* End of fields guarded by root rcu_node's lock. */ |