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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-05-07 12:07:48 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-07-12 15:39:07 -0700 |
| commit | e05121ba5b81e2f85349f038642410578457f6db (patch) | |
| tree | a92f11a94cf28b98673e40182020435730cea6fc /kernel/rcu | |
| parent | rcu: Remove failsafe check for lost quiescent state (diff) | |
| download | linux-dev-e05121ba5b81e2f85349f038642410578457f6db.tar.xz linux-dev-e05121ba5b81e2f85349f038642410578457f6db.zip | |
rcu: Remove CPU-hotplug failsafe from force-quiescent-state code path
Now that quiescent states for newly offlined CPUs are reported either
when that CPU goes offline or at the end of grace-period initialization,
the CPU-hotplug failsafe in the force-quiescent-state code path is no
longer needed.
This commit therefore removes this failsafe.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 9 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 1 |
2 files changed, 1 insertions, 9 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 770f0df54015..5f1a11f1f7bc 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1188,14 +1188,6 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) smp_store_release(ruqp, true); } - /* Check for the CPU being offline. */ - if (!(rdp->grpmask & rcu_rnp_online_cpus(rnp))) { - trace_rcu_fqs(rdp->rsp->name, rdp->gp_seq, rdp->cpu, TPS("ofl")); - rdp->offline_fqs++; - rcu_gpnum_ovf(rnp, rdp); - return 1; - } - /* * A CPU running for an extended time within the kernel can * delay RCU grace periods. When the CPU is in NO_HZ_FULL mode, @@ -3718,6 +3710,7 @@ void rcu_cpu_starting(unsigned int cpu) nbits = bitmap_weight(&oldmask, BITS_PER_LONG); /* Allow lockless access for expedited grace periods. */ smp_store_release(&rsp->ncpus, rsp->ncpus + nbits); /* ^^^ */ + rcu_gpnum_ovf(rnp, rdp); /* Offline-induced counter wrap? */ if (rnp->qsmask & mask) { /* RCU waiting on incoming CPU? */ /* Report QS -after- changing ->qsmaskinitnext! */ rcu_report_qs_rnp(mask, rsp, rnp, rnp->gp_seq, flags); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 6683da6e4ecc..795d469c6f67 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -217,7 +217,6 @@ struct rcu_data { /* 4) reasons this CPU needed to be kicked by force_quiescent_state */ unsigned long dynticks_fqs; /* Kicked due to dynticks idle. */ - unsigned long offline_fqs; /* Kicked due to being offline. */ unsigned long cond_resched_completed; /* Grace period that needs help */ /* from cond_resched(). */ |