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| author |   Frederic Weisbecker <frederic@kernel.org> | 2024-07-04 00:56:40 +0200 |
|---|---|---|
| committer |   Neeraj Upadhyay <neeraj.upadhyay@kernel.org> | 2024-09-09 00:03:55 +0530 |
| commit | 1fcb932c8b5ce86219d7dedcd63659351a43291c (patch) | |
| tree | 8fdee9206d294e08c9f6808aad832f5b6751a152 /include | |
| parent | rcu/nocb: Remove SEGCBLIST_KTHREAD_CB (diff) | |
| download | wireguard-linux-1fcb932c8b5ce86219d7dedcd63659351a43291c.tar.xz wireguard-linux-1fcb932c8b5ce86219d7dedcd63659351a43291c.zip | |
rcu/nocb: Simplify (de-)offloading state machine
Now that the (de-)offloading process can only apply to offline CPUs,
there is no more concurrency between rcu_core and nocb kthreads. Also
the mutation now happens on empty queues.
Therefore the state machine can be reduced to a single bit called
SEGCBLIST_OFFLOADED. Simplify the transition as follows:
* Upon offloading: queue the rdp to be added to the rcuog list and
wait for the rcuog kthread to set the SEGCBLIST_OFFLOADED bit. Unpark
rcuo kthread.
* Upon de-offloading: Park rcuo kthread. Queue the rdp to be removed
from the rcuog list and wait for the rcuog kthread to clear the
SEGCBLIST_OFFLOADED bit.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rcu_segcblist.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h index 1ef1bb54853d..2fdc2208f1ca 100644 --- a/include/linux/rcu_segcblist.h +++ b/include/linux/rcu_segcblist.h @@ -185,9 +185,7 @@ struct rcu_cblist { * ---------------------------------------------------------------------------- */ #define SEGCBLIST_ENABLED BIT(0) -#define SEGCBLIST_LOCKING BIT(1) -#define SEGCBLIST_KTHREAD_GP BIT(2) -#define SEGCBLIST_OFFLOADED BIT(3) +#define SEGCBLIST_OFFLOADED BIT(1) struct rcu_segcblist { struct rcu_head *head; |