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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-06-29 17:04:19 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-08-22 09:30:42 -0700 |
| commit | 98834b83785e1388fa8672cf4f8de09974d15e86 (patch) | |
| tree | 0d5e2ac04b2ee8785674c4471c9ddae07d728174 /kernel/rcu | |
| parent | 24a6cff286030b98149ff10b968cba31280fcb7a (diff) | |
| download | linux-98834b83785e1388fa8672cf4f8de09974d15e86.tar.gz linux-98834b83785e1388fa8672cf4f8de09974d15e86.tar.bz2 linux-98834b83785e1388fa8672cf4f8de09974d15e86.zip | |
rcu: Exclude RCU-offline CPUs from expedited grace periods
The expedited RCU grace periods currently rely on a failure indication
from smp_call_function_single() to determine that a given CPU is offline.
This works after a fashion, but is more contorted and less precise than
relying on RCU's internal state. This commit therefore takes a first
step towards relying on internal state.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index f316683b18f1..3bc4b3dda801 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -359,7 +359,8 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp, struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); if (raw_smp_processor_id() == cpu || - !(atomic_add_return(0, &rdtp->dynticks) & 0x1)) + !(atomic_add_return(0, &rdtp->dynticks) & 0x1) || + !(rnp->qsmaskinitnext & rdp->grpmask)) mask_ofl_test |= rdp->grpmask; } mask_ofl_ipi = rnp->expmask & ~mask_ofl_test; |