diff options
Diffstat (limited to 'rcu-avoid-just-onlined-cpu-resched.patch')
| -rw-r--r-- | rcu-avoid-just-onlined-cpu-resched.patch | 47 |
1 files changed, 0 insertions, 47 deletions
diff --git a/rcu-avoid-just-onlined-cpu-resched.patch b/rcu-avoid-just-onlined-cpu-resched.patch deleted file mode 100644 index 517f37591..000000000 --- a/rcu-avoid-just-onlined-cpu-resched.patch +++ /dev/null @@ -1,47 +0,0 @@ -rcu: Avoid having just-onlined CPU resched itself when RCU is idle - -CPUs set rdp->qs_pending when coming online to resolve races with -grace-period start. However, this means that if RCU is idle, the -just-onlined CPU might needlessly send itself resched IPIs. Adjust -the online-CPU initialization to avoid this, and also to correctly -cause the CPU to respond to the current grace period if needed. - -Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> ---- - kernel/rcutree.c | 13 +++++++++---- - 1 files changed, 9 insertions(+), 4 deletions(-) - -diff --git a/kernel/rcutree.c b/kernel/rcutree.c -index ba06207..472d6b2 100644 ---- a/kernel/rcutree.c -+++ b/kernel/rcutree.c -@@ -1865,8 +1865,6 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible) - - /* Set up local state, ensuring consistent view of global state. */ - raw_spin_lock_irqsave(&rnp->lock, flags); -- rdp->passed_quiesc = 0; /* We could be racing with new GP, */ -- rdp->qs_pending = 1; /* so set up to respond to current GP. */ - rdp->beenonline = 1; /* We have now been online. */ - rdp->preemptible = preemptible; - rdp->qlen_last_fqs_check = 0; -@@ -1891,8 +1889,15 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible) - rnp->qsmaskinit |= mask; - mask = rnp->grpmask; - if (rnp == rdp->mynode) { -- rdp->gpnum = rnp->completed; /* if GP in progress... */ -- rdp->completed = rnp->completed; -+ /* -+ * If there is a grace period in progress, we will -+ * set up to wait for it next time we run the -+ * RCU core code. -+ */ -+ rdp->gpnum = rnp->completed; -+ rdp->completed = rnp->completed; -+ rdp->passed_quiesc = 0; -+ rdp->qs_pending = 0; - rdp->passed_quiesc_completed = rnp->completed - 1; - } - raw_spin_unlock(&rnp->lock); /* irqs already disabled. */ --- -1.7.6 - |