[PATCH] eventfd: Replace rcu_assign_pointer() with RCU_INIT_POINTER()

From: Andreea-Cristina Bernat
Date: Mon Aug 18 2014 - 11:01:43 EST


The uses of "rcu_assign_pointer()" are NULLing out the pointers.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@xxxxxxxxx>
---
virt/kvm/eventfd.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 20c3af7..a49130f 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -278,7 +278,7 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd,
struct kvm_kernel_irq_routing_entry *e;

if (irqfd->gsi >= irq_rt->nr_rt_entries) {
- rcu_assign_pointer(irqfd->irq_entry, NULL);
+ RCU_INIT_POINTER(irqfd->irq_entry, NULL);
return;
}

@@ -287,7 +287,7 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd,
if (e->type == KVM_IRQ_ROUTING_MSI)
rcu_assign_pointer(irqfd->irq_entry, e);
else
- rcu_assign_pointer(irqfd->irq_entry, NULL);
+ RCU_INIT_POINTER(irqfd->irq_entry, NULL);
}
}

@@ -473,7 +473,7 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
* It is paired with synchronize_srcu done by caller
* of that function.
*/
- rcu_assign_pointer(irqfd->irq_entry, NULL);
+ RCU_INIT_POINTER(irqfd->irq_entry, NULL);
irqfd_deactivate(irqfd);
}
}
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/