[PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[Yuval Shaia]

Signed-off-by: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
v0 -> v1:
	* s/"min_t("/"min_t(int"
v1 -> v2:
	* Use min3 instead of min_t twice
v2 -> v3:
	* Change commit log header message to reflect the changes made in
	  v2
v3 -> v4:
	* Cast return value from num_online_cpus to int to avoid
	  compilation errors from "sparse"
---
 drivers/net/ethernet/mellanox/mlx4/main.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 7032054..83aab1e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -2862,12 +2862,10 @@ static void mlx4_enable_msi_x(struct mlx4_dev *dev)
 	int port = 0;
 
 	if (msi_x) {
-		int nreq = dev->caps.num_ports * num_online_cpus() + 1;
-
-		nreq = min_t(int, dev->caps.num_eqs - dev->caps.reserved_eqs,
-			     nreq);
-		if (nreq > MAX_MSIX)
-			nreq = MAX_MSIX;
+		int nreq = min3(dev->caps.num_ports *
+				(int)num_online_cpus() + 1,
+				dev->caps.num_eqs - dev->caps.reserved_eqs,
+				MAX_MSIX);
 
 		entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL);
 		if (!entries)
-- 
2.7.4

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Re: [PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[Yuval Shaia]

On Fri, May 12, 2017 at 09:10:51AM +0300, Yuval Shaia wrote:
> Signed-off-by: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> ---
> v0 -> v1:
> 	* s/"min_t("/"min_t(int"
> v1 -> v2:
> 	* Use min3 instead of min_t twice
> v2 -> v3:
> 	* Change commit log header message to reflect the changes made in
> 	  v2
> v3 -> v4:
> 	* Cast return value from num_online_cpus to int to avoid
> 	  compilation errors from "sparse"

Hi Leon,
Got your r-b for v3, can you please review v4?

Thanks,

> ---
>  drivers/net/ethernet/mellanox/mlx4/main.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
> index 7032054..83aab1e 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/main.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/main.c
> @@ -2862,12 +2862,10 @@ static void mlx4_enable_msi_x(struct mlx4_dev *dev)
>  	int port = 0;
>  
>  	if (msi_x) {
> -		int nreq = dev->caps.num_ports * num_online_cpus() + 1;
> -
> -		nreq = min_t(int, dev->caps.num_eqs - dev->caps.reserved_eqs,
> -			     nreq);
> -		if (nreq > MAX_MSIX)
> -			nreq = MAX_MSIX;
> +		int nreq = min3(dev->caps.num_ports *
> +				(int)num_online_cpus() + 1,
> +				dev->caps.num_eqs - dev->caps.reserved_eqs,
> +				MAX_MSIX);
>  
>  		entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL);
>  		if (!entries)
> -- 
> 2.7.4
> 
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Re: [PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[Leon Romanovsky]

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On Sun, May 14, 2017 at 10:01:34PM +0300, Yuval Shaia wrote:
> On Fri, May 12, 2017 at 09:10:51AM +0300, Yuval Shaia wrote:
> > Signed-off-by: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> > ---
> > v0 -> v1:
> > 	* s/"min_t("/"min_t(int"
> > v1 -> v2:
> > 	* Use min3 instead of min_t twice
> > v2 -> v3:
> > 	* Change commit log header message to reflect the changes made in
> > 	  v2
> > v3 -> v4:
> > 	* Cast return value from num_online_cpus to int to avoid
> > 	  compilation errors from "sparse"
>
> Hi Leon,
> Got your r-b for v3, can you please review v4?

What was the sparse error?

num_online_cpus() is declared as "unsigned int", so you don't need to do casting.

➜  linux-rdma git:(master) git grep num_online_cpus include/
include/linux/cpumask.h:#define num_online_cpus()       cpumask_weight(cpu_online_mask)
include/linux/cpumask.h:#define num_online_cpus()       1U

➜  linux-rdma git:(master) git grep cpumask_weight include/
include/linux/cpumask.h:static inline unsigned int cpumask_weight(const struct cpumask *srcp)

Thanks

>
> Thanks,
>
> > ---
> >  drivers/net/ethernet/mellanox/mlx4/main.c | 10 ++++------
> >  1 file changed, 4 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
> > index 7032054..83aab1e 100644
> > --- a/drivers/net/ethernet/mellanox/mlx4/main.c
> > +++ b/drivers/net/ethernet/mellanox/mlx4/main.c
> > @@ -2862,12 +2862,10 @@ static void mlx4_enable_msi_x(struct mlx4_dev *dev)
> >  	int port = 0;
> >
> >  	if (msi_x) {
> > -		int nreq = dev->caps.num_ports * num_online_cpus() + 1;
> > -
> > -		nreq = min_t(int, dev->caps.num_eqs - dev->caps.reserved_eqs,
> > -			     nreq);
> > -		if (nreq > MAX_MSIX)
> > -			nreq = MAX_MSIX;
> > +		int nreq = min3(dev->caps.num_ports *
> > +				(int)num_online_cpus() + 1,
> > +				dev->caps.num_eqs - dev->caps.reserved_eqs,
> > +				MAX_MSIX);
> >
> >  		entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL);
> >  		if (!entries)
> > --
> > 2.7.4
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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Re: [PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[Yuval Shaia]

On Mon, May 15, 2017 at 07:43:04AM +0300, Leon Romanovsky wrote:
> On Sun, May 14, 2017 at 10:01:34PM +0300, Yuval Shaia wrote:
> > On Fri, May 12, 2017 at 09:10:51AM +0300, Yuval Shaia wrote:
> > > Signed-off-by: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> > > ---
> > > v0 -> v1:
> > > 	* s/"min_t("/"min_t(int"
> > > v1 -> v2:
> > > 	* Use min3 instead of min_t twice
> > > v2 -> v3:
> > > 	* Change commit log header message to reflect the changes made in
> > > 	  v2
> > > v3 -> v4:
> > > 	* Cast return value from num_online_cpus to int to avoid
> > > 	  compilation errors from "sparse"
> >
> > Hi Leon,
> > Got your r-b for v3, can you please review v4?
> 
> What was the sparse error?
> 
> num_online_cpus() is declared as "unsigned int", so you don't need to do casting.
> 
> ➜  linux-rdma git:(master) git grep num_online_cpus include/
> include/linux/cpumask.h:#define num_online_cpus()       cpumask_weight(cpu_online_mask)
> include/linux/cpumask.h:#define num_online_cpus()       1U
> 
> ➜  linux-rdma git:(master) git grep cpumask_weight include/
> include/linux/cpumask.h:static inline unsigned int cpumask_weight(const struct cpumask *srcp)

But num_eqs and reserved_eqs are ints so assuming the error is that i
asked min3 to compare unsigned int with int.

This casting cannot do harm because anyway the result is stored in int
variable.

> 
> Thanks
> 
> >
> > Thanks,
> >
> > > ---
> > >  drivers/net/ethernet/mellanox/mlx4/main.c | 10 ++++------
> > >  1 file changed, 4 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
> > > index 7032054..83aab1e 100644
> > > --- a/drivers/net/ethernet/mellanox/mlx4/main.c
> > > +++ b/drivers/net/ethernet/mellanox/mlx4/main.c
> > > @@ -2862,12 +2862,10 @@ static void mlx4_enable_msi_x(struct mlx4_dev *dev)
> > >  	int port = 0;
> > >
> > >  	if (msi_x) {
> > > -		int nreq = dev->caps.num_ports * num_online_cpus() + 1;
> > > -
> > > -		nreq = min_t(int, dev->caps.num_eqs - dev->caps.reserved_eqs,
> > > -			     nreq);
> > > -		if (nreq > MAX_MSIX)
> > > -			nreq = MAX_MSIX;
> > > +		int nreq = min3(dev->caps.num_ports *
> > > +				(int)num_online_cpus() + 1,
> > > +				dev->caps.num_eqs - dev->caps.reserved_eqs,
> > > +				MAX_MSIX);
> > >
> > >  		entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL);
> > >  		if (!entries)
> > > --
> > > 2.7.4
> > >
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> > > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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> > --
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Re: [PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[Leon Romanovsky]

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On Mon, May 15, 2017 at 10:53:24AM +0300, Yuval Shaia wrote:
> On Mon, May 15, 2017 at 07:43:04AM +0300, Leon Romanovsky wrote:
> > On Sun, May 14, 2017 at 10:01:34PM +0300, Yuval Shaia wrote:
> > > On Fri, May 12, 2017 at 09:10:51AM +0300, Yuval Shaia wrote:
> > > > Signed-off-by: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> > > > ---
> > > > v0 -> v1:
> > > > 	* s/"min_t("/"min_t(int"
> > > > v1 -> v2:
> > > > 	* Use min3 instead of min_t twice
> > > > v2 -> v3:
> > > > 	* Change commit log header message to reflect the changes made in
> > > > 	  v2
> > > > v3 -> v4:
> > > > 	* Cast return value from num_online_cpus to int to avoid
> > > > 	  compilation errors from "sparse"
> > >
> > > Hi Leon,
> > > Got your r-b for v3, can you please review v4?
> >
> > What was the sparse error?
> >
> > num_online_cpus() is declared as "unsigned int", so you don't need to do casting.
> >
> > ➜  linux-rdma git:(master) git grep num_online_cpus include/
> > include/linux/cpumask.h:#define num_online_cpus()       cpumask_weight(cpu_online_mask)
> > include/linux/cpumask.h:#define num_online_cpus()       1U
> >
> > ➜  linux-rdma git:(master) git grep cpumask_weight include/
> > include/linux/cpumask.h:static inline unsigned int cpumask_weight(const struct cpumask *srcp)
>
> But num_eqs and reserved_eqs are ints so assuming the error is that i
> asked min3 to compare unsigned int with int.
>
> This casting cannot do harm because anyway the result is stored in int
> variable.

Thanks,
Reviewed-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

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Re: [PATCH v4] net/mlx4_core: Use min3 to select number of MSI-X vectors

[David Miller]

From: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Date: Fri, 12 May 2017 09:10:51 +0300

> Signed-off-by: Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> ---
> v0 -> v1:
> 	* s/"min_t("/"min_t(int"
> v1 -> v2:
> 	* Use min3 instead of min_t twice
> v2 -> v3:
> 	* Change commit log header message to reflect the changes made in
> 	  v2
> v3 -> v4:
> 	* Cast return value from num_online_cpus to int to avoid
> 	  compilation errors from "sparse"

Applied, thanks.
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