diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2024-10-25 15:56:17 -0700 |
|---|---|---|
| committer | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2024-12-14 17:10:07 +0100 |
| commit | e2bd168295e4eb719a343086baddfe0abca512a2 (patch) | |
| tree | 9e46e5e577ecca41544aa5e52b1e8ed01b574c84 /kernel/rcu | |
| parent | d16e32f75f30d5228d9e0a3f6ca77b62c3a4383d (diff) | |
rcu: Move rcu_report_exp_rdp() setting of ->cpu_no_qs.b.exp under lock
This commit reduces the state space of rcu_report_exp_rdp() by moving
the setting of ->cpu_no_qs.b.exp under the rcu_node structure's ->lock.
The lock isn't really all that important here, given that this per-CPU
field is supposed to be written only by its CPU, but the disabling of
interrupts excludes things like rcu_exp_handler(), which also can write
to this same field. Avoiding this sort of interleaved access reduces
the state space.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 581e88d39542..5c4ea66cc00d 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -260,8 +260,8 @@ static void rcu_report_exp_rdp(struct rcu_data *rdp) unsigned long flags; struct rcu_node *rnp = rdp->mynode; - WRITE_ONCE(rdp->cpu_no_qs.b.exp, false); raw_spin_lock_irqsave_rcu_node(rnp, flags); + WRITE_ONCE(rdp->cpu_no_qs.b.exp, false); rcu_report_exp_cpu_mult(rnp, flags, rdp->grpmask, true); } |