* [PATCH 1/1] iommu: to avoid an unnecessary assignment
@ 2017-02-03 9:35 Zhen Lei
2017-02-03 11:34 ` Robin Murphy
2017-02-06 13:07 ` Joerg Roedel
0 siblings, 2 replies; 3+ messages in thread
From: Zhen Lei @ 2017-02-03 9:35 UTC (permalink / raw)
To: Joerg Roedel, iommu, linux-kernel
Cc: Zefan Li, Xinwei Hu, Tianhong Ding, Hanjun Guo, Zhen Lei
Move the assignment statement into if branch above, where it only
needs to be.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
drivers/iommu/iommu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index dbe7f65..b231400 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1714,13 +1714,14 @@ int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids)
fwspec = krealloc(dev->iommu_fwspec, size, GFP_KERNEL);
if (!fwspec)
return -ENOMEM;
+
+ dev->iommu_fwspec = fwspec;
}
for (i = 0; i < num_ids; i++)
fwspec->ids[fwspec->num_ids + i] = ids[i];
fwspec->num_ids += num_ids;
- dev->iommu_fwspec = fwspec;
return 0;
}
EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
--
2.5.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/1] iommu: to avoid an unnecessary assignment
2017-02-03 9:35 [PATCH 1/1] iommu: to avoid an unnecessary assignment Zhen Lei
@ 2017-02-03 11:34 ` Robin Murphy
2017-02-06 13:07 ` Joerg Roedel
1 sibling, 0 replies; 3+ messages in thread
From: Robin Murphy @ 2017-02-03 11:34 UTC (permalink / raw)
To: Zhen Lei, Joerg Roedel, iommu, linux-kernel
Cc: Xinwei Hu, Zefan Li, Hanjun Guo, Tianhong Ding
On 03/02/17 09:35, Zhen Lei wrote:
> Move the assignment statement into if branch above, where it only
> needs to be.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
> drivers/iommu/iommu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index dbe7f65..b231400 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -1714,13 +1714,14 @@ int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids)
> fwspec = krealloc(dev->iommu_fwspec, size, GFP_KERNEL);
> if (!fwspec)
> return -ENOMEM;
> +
> + dev->iommu_fwspec = fwspec;
> }
>
> for (i = 0; i < num_ids; i++)
> fwspec->ids[fwspec->num_ids + i] = ids[i];
>
> fwspec->num_ids += num_ids;
> - dev->iommu_fwspec = fwspec;
Strictly, it was done here because I like following transactional
idioms, i.e. at any point dev->fwspec is either the old one or the
fully-initialised new one. However, since the state of the new one
immediately after realloc isn't uninitialised, but still directly
equivalent to the old one, I don't see an issue with moving the
assignemnt there, plus it does avoid a redundant reassignment the first
time through.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> return 0;
> }
> EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
> --
> 2.5.0
>
>
> _______________________________________________
> iommu mailing list
> iommu@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/1] iommu: to avoid an unnecessary assignment
2017-02-03 9:35 [PATCH 1/1] iommu: to avoid an unnecessary assignment Zhen Lei
2017-02-03 11:34 ` Robin Murphy
@ 2017-02-06 13:07 ` Joerg Roedel
1 sibling, 0 replies; 3+ messages in thread
From: Joerg Roedel @ 2017-02-06 13:07 UTC (permalink / raw)
To: Zhen Lei
Cc: iommu, linux-kernel, Zefan Li, Xinwei Hu, Tianhong Ding, Hanjun Guo
On Fri, Feb 03, 2017 at 05:35:02PM +0800, Zhen Lei wrote:
> Move the assignment statement into if branch above, where it only
> needs to be.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
> drivers/iommu/iommu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
Applied, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
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