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* [PATCH] iommu: Replace rcu_assign_pointer() with RCU_INIT_POINTER()
@ 2014-08-18 12:20 Andreea-Cristina Bernat
  2014-08-19 11:31 ` Joerg Roedel
  0 siblings, 1 reply; 2+ messages in thread
From: Andreea-Cristina Bernat @ 2014-08-18 12:20 UTC (permalink / raw)
  To: joro, iommu, linux-kernel; +Cc: paulmck

The use of "rcu_assign_pointer()" is NULLing out the pointer.
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@gmail.com>
---
 drivers/iommu/dmar.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 9a4f05e..da9220b 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -246,7 +246,7 @@ int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment,
 
 	for_each_active_dev_scope(devices, count, index, tmp)
 		if (tmp == &info->dev->dev) {
-			rcu_assign_pointer(devices[index].dev, NULL);
+			RCU_INIT_POINTER(devices[index].dev, NULL);
 			synchronize_rcu();
 			put_device(tmp);
 			return 1;
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] iommu: Replace rcu_assign_pointer() with RCU_INIT_POINTER()
  2014-08-18 12:20 [PATCH] iommu: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Andreea-Cristina Bernat
@ 2014-08-19 11:31 ` Joerg Roedel
  0 siblings, 0 replies; 2+ messages in thread
From: Joerg Roedel @ 2014-08-19 11:31 UTC (permalink / raw)
  To: Andreea-Cristina Bernat; +Cc: iommu, linux-kernel, paulmck

On Mon, Aug 18, 2014 at 03:20:56PM +0300, Andreea-Cristina Bernat wrote:
> The use of "rcu_assign_pointer()" is NULLing out the pointer.
> 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@gmail.com>

Applied, thanks.


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2014-08-18 12:20 [PATCH] iommu: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Andreea-Cristina Bernat
2014-08-19 11:31 ` Joerg Roedel

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