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| author | Neeraj Upadhyay <neeraju@codeaurora.org> | 2020-06-22 23:37:03 +0530 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-08-24 18:36:06 -0700 |
| commit | 9b1ce0acb5e65e9ea1e6b322562d072f9f7d1f6e (patch) | |
| tree | 9d482e8ce8e7d0df0baca05fbdd569e7f26f22f3 /kernel | |
| parent | 9c39245382de4d52a122641952900709d4a9950b (diff) | |
| download | linux-stable-9b1ce0acb5e65e9ea1e6b322562d072f9f7d1f6e.tar.gz linux-stable-9b1ce0acb5e65e9ea1e6b322562d072f9f7d1f6e.tar.bz2 linux-stable-9b1ce0acb5e65e9ea1e6b322562d072f9f7d1f6e.zip | |
rcu/tree: Remove CONFIG_PREMPT_RCU check in force_qs_rnp()
Originally, the call to rcu_preempt_blocked_readers_cgp() from
force_qs_rnp() had to be conditioned on CONFIG_PREEMPT_RCU=y, as in
commit a77da14ce9af ("rcu: Yet another fix for preemption and CPU
hotplug"). However, there is now a CONFIG_PREEMPT_RCU=n definition of
rcu_preempt_blocked_readers_cgp() that unconditionally returns zero, so
invoking it is now safe. In addition, the CONFIG_PREEMPT_RCU=n definition
of rcu_initiate_boost() simply releases the rcu_node structure's ->lock,
which is what happens when the "if" condition evaluates to false.
This commit therefore drops the IS_ENABLED(CONFIG_PREEMPT_RCU) check,
so that rcu_initiate_boost() is called only in CONFIG_PREEMPT_RCU=y
kernels when there are readers blocking the current grace period.
This does not change the behavior, but reduces code-reader confusion by
eliminating non-CONFIG_PREEMPT_RCU=y calls to rcu_initiate_boost().
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 4770d7709dc2..acc926f07dc1 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2533,8 +2533,7 @@ static void force_qs_rnp(int (*f)(struct rcu_data *rdp)) raw_spin_lock_irqsave_rcu_node(rnp, flags); rcu_state.cbovldnext |= !!rnp->cbovldmask; if (rnp->qsmask == 0) { - if (!IS_ENABLED(CONFIG_PREEMPT_RCU) || - rcu_preempt_blocked_readers_cgp(rnp)) { + if (rcu_preempt_blocked_readers_cgp(rnp)) { /* * No point in scanning bits because they * are all zero. But we might need to |