Messages in this thread Patch in this message | | | From | Pranith Kumar <> | Subject | [PATCH 1/1] rcu: Check for have_rcu_nocb_mask instead of rcu_nocb_mask | Date | Thu, 17 Jul 2014 17:30:11 -0400 |
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Hi Paul,
This is something similar to what you found yesterday with tick_nohz_full mask.
-- Pranith
If we configure a kernel with CONFIG_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_NONE=y and CONFIG_CPUMASK_OFFSTACK=n and do not pass in a rcu_nocb= boot parameter, the cpumask rcu_nocb_mask can be garbage instead of NULL.
Hence this commit replaces checks for rcu_nocb_mask == NULL with a check for have_rcu_nocb_mask.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> --- kernel/rcu/tree_plugin.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index cedb020..15c00b5 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2542,7 +2542,7 @@ static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp) struct rcu_data *rdp_leader = NULL; /* Suppress misguided gcc warn. */ struct rcu_data *rdp_prev = NULL; - if (rcu_nocb_mask == NULL) + if (!have_rcu_nocb_mask) return; #ifdef CONFIG_NO_HZ_FULL cpumask_or(rcu_nocb_mask, rcu_nocb_mask, tick_nohz_full_mask); @@ -2575,7 +2575,7 @@ static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp) /* Prevent __call_rcu() from enqueuing callbacks on no-CBs CPUs */ static bool init_nocb_callback_list(struct rcu_data *rdp) { - if (rcu_nocb_mask == NULL || + if (have_rcu_nocb_mask == false || !cpumask_test_cpu(rdp->cpu, rcu_nocb_mask)) return false; rdp->nxttail[RCU_NEXT_TAIL] = NULL; -- 1.9.1
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