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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-02-22 20:07:09 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-04-27 11:01:16 -0700 |
| commit | 1fca4d12f46371a34bf90af87f49548dd026c3ca (patch) | |
| tree | 311125bf4cec30f94fb44dc3e00ffa9bda81432a /kernel/rcu/tree.h | |
| parent | 53965dbe5396d2945c7cf53c77c7b5532b08791c (diff) | |
rcu: Expedite first two FQS scans under callback-overload conditions
Even if some CPUs have excessive numbers of callbacks, RCU's grace-period
kthread will still wait normally between successive force-quiescent-state
scans. The first two are the most important, as they are the ones that
enlist aid from the scheduler when overloaded. This commit therefore
omits the wait before the first and the second force-quiescent-state
scan under callback-overload conditions.
This approach was inspired by a discussion with Jeff Roberson.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 9dc2ec021da5..44edd0a98ffe 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -359,6 +359,7 @@ struct rcu_state { /* Values for rcu_state structure's gp_flags field. */ #define RCU_GP_FLAG_INIT 0x1 /* Need grace-period initialization. */ #define RCU_GP_FLAG_FQS 0x2 /* Need grace-period quiescent-state forcing. */ +#define RCU_GP_FLAG_OVLD 0x4 /* Experiencing callback overload. */ /* Values for rcu_state structure's gp_state field. */ #define RCU_GP_IDLE 0 /* Initial state and no GP in progress. */ |