Re: [RFC 1/4] net: allow large number of rx queues

2014-08-18 Thread Pankaj Gupta 

> Hello.
> 
> On 08/18/2014 05:37 PM, Pankaj Gupta wrote:
> 
> > netif_alloc_rx_queues() uses kcalloc() to allocate memory
> > for "struct netdev_queue *_rx" array.
> > If we are doing large rx queue allocation kcalloc() might
> > fail, so this patch does a fallback to vzalloc().
> > Similar implementation is done for tx queue allocation in
> > netif_alloc_netdev_queues().
> 
> > We avoid failure of high order memory allocation
> > with the help of vzalloc(), this allows us to do large
> > rx and tx queue allocation which in turn helps us to
> > increase the number of queues in tun.
> 
> > As vmalloc() adds overhead on a critical network path,
> > __GFP_REPEAT flag is used with kzalloc() to do this fallback
> > only when really needed.
> 
> > Signed-off-by: Pankaj Gupta 
> > Reviewed-by: Michael S. Tsirkin 
> > Reviewed-by: David Gibson 
> > ---
> >   net/core/dev.c | 20 +---
> >   1 file changed, 13 insertions(+), 7 deletions(-)
> 
> > diff --git a/net/core/dev.c b/net/core/dev.c
> > index 1c15b18..a455a02 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct
> > net_device *rootdev,
> >   EXPORT_SYMBOL(netif_stacked_transfer_operstate);
> >
> >   #ifdef CONFIG_SYSFS
> > +static void netif_free_rx_queues(struct net_device *dev)
> > +{
> > +   kvfree(dev->_rx);
> > +}
> > +
> >   static int netif_alloc_rx_queues(struct net_device *dev)
> >   {
> > unsigned int i, count = dev->num_rx_queues;
> > struct netdev_rx_queue *rx;
> > -
> > +   size_t sz = count * sizeof(*rx);
> 
>Please keep an empty line after declarations.
 Yes, I will add it. Thanks
> 
> > BUG_ON(count < 1);
> >
> 
> WBR, Sergei
> 
> 
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Re: [RFC 1/4] net: allow large number of rx queues

2014-08-18 Thread Sergei Shtylyov 

Hello.

On 08/18/2014 05:37 PM, Pankaj Gupta wrote:


netif_alloc_rx_queues() uses kcalloc() to allocate memory
for "struct netdev_queue *_rx" array.
If we are doing large rx queue allocation kcalloc() might
fail, so this patch does a fallback to vzalloc().
Similar implementation is done for tx queue allocation in
netif_alloc_netdev_queues().



We avoid failure of high order memory allocation
with the help of vzalloc(), this allows us to do large
rx and tx queue allocation which in turn helps us to
increase the number of queues in tun.



As vmalloc() adds overhead on a critical network path,
__GFP_REPEAT flag is used with kzalloc() to do this fallback
only when really needed.



Signed-off-by: Pankaj Gupta 
Reviewed-by: Michael S. Tsirkin 
Reviewed-by: David Gibson 
---
  net/core/dev.c | 20 +---
  1 file changed, 13 insertions(+), 7 deletions(-)



diff --git a/net/core/dev.c b/net/core/dev.c
index 1c15b18..a455a02 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct 
net_device *rootdev,
  EXPORT_SYMBOL(netif_stacked_transfer_operstate);

  #ifdef CONFIG_SYSFS
+static void netif_free_rx_queues(struct net_device *dev)
+{
+   kvfree(dev->_rx);
+}
+
  static int netif_alloc_rx_queues(struct net_device *dev)
  {
unsigned int i, count = dev->num_rx_queues;
struct netdev_rx_queue *rx;
-
+   size_t sz = count * sizeof(*rx);


  Please keep an empty line after declarations.


BUG_ON(count < 1);



WBR, Sergei

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[RFC 1/4] net: allow large number of rx queues

2014-08-18 Thread Pankaj Gupta 
netif_alloc_rx_queues() uses kcalloc() to allocate memory
for "struct netdev_queue *_rx" array.
If we are doing large rx queue allocation kcalloc() might
fail, so this patch does a fallback to vzalloc().
Similar implementation is done for tx queue allocation in
netif_alloc_netdev_queues().

We avoid failure of high order memory allocation
with the help of vzalloc(), this allows us to do large
rx and tx queue allocation which in turn helps us to
increase the number of queues in tun.

As vmalloc() adds overhead on a critical network path,
__GFP_REPEAT flag is used with kzalloc() to do this fallback
only when really needed.

Signed-off-by: Pankaj Gupta 
Reviewed-by: Michael S. Tsirkin 
Reviewed-by: David Gibson 
---
 net/core/dev.c | 20 +---
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 1c15b18..a455a02 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct 
net_device *rootdev,
 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
 
 #ifdef CONFIG_SYSFS
+static void netif_free_rx_queues(struct net_device *dev)
+{
+   kvfree(dev->_rx);
+}
+
 static int netif_alloc_rx_queues(struct net_device *dev)
 {
unsigned int i, count = dev->num_rx_queues;
struct netdev_rx_queue *rx;
-
+   size_t sz = count * sizeof(*rx);
BUG_ON(count < 1);
 
-   rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
-   if (!rx)
-   return -ENOMEM;
-
+   rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+   if (!rx) {
+   rx = vzalloc(sz);
+   if (!rx)
+   return -ENOMEM;
+   }
dev->_rx = rx;
 
for (i = 0; i < count; i++)
@@ -6581,9 +6588,8 @@ void free_netdev(struct net_device *dev)
 
netif_free_tx_queues(dev);
 #ifdef CONFIG_SYSFS
-   kfree(dev->_rx);
+   netif_free_rx_queues(dev);
 #endif
-
kfree(rcu_dereference_protected(dev->ingress_queue, 1));
 
/* Flush device addresses */
-- 
1.8.3.1

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[RFC 1/4] net: allow large number of rx queues

2014-08-18 Thread Pankaj Gupta 
netif_alloc_rx_queues() uses kcalloc() to allocate memory
for struct netdev_queue *_rx array.
If we are doing large rx queue allocation kcalloc() might
fail, so this patch does a fallback to vzalloc().
Similar implementation is done for tx queue allocation in
netif_alloc_netdev_queues().

We avoid failure of high order memory allocation
with the help of vzalloc(), this allows us to do large
rx and tx queue allocation which in turn helps us to
increase the number of queues in tun.

As vmalloc() adds overhead on a critical network path,
__GFP_REPEAT flag is used with kzalloc() to do this fallback
only when really needed.

Signed-off-by: Pankaj Gupta pagu...@redhat.com
Reviewed-by: Michael S. Tsirkin m...@redhat.com
Reviewed-by: David Gibson dgib...@redhat.com
---
 net/core/dev.c | 20 +---
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 1c15b18..a455a02 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct 
net_device *rootdev,
 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
 
 #ifdef CONFIG_SYSFS
+static void netif_free_rx_queues(struct net_device *dev)
+{
+   kvfree(dev-_rx);
+}
+
 static int netif_alloc_rx_queues(struct net_device *dev)
 {
unsigned int i, count = dev-num_rx_queues;
struct netdev_rx_queue *rx;
-
+   size_t sz = count * sizeof(*rx);
BUG_ON(count  1);
 
-   rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
-   if (!rx)
-   return -ENOMEM;
-
+   rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+   if (!rx) {
+   rx = vzalloc(sz);
+   if (!rx)
+   return -ENOMEM;
+   }
dev-_rx = rx;
 
for (i = 0; i  count; i++)
@@ -6581,9 +6588,8 @@ void free_netdev(struct net_device *dev)
 
netif_free_tx_queues(dev);
 #ifdef CONFIG_SYSFS
-   kfree(dev-_rx);
+   netif_free_rx_queues(dev);
 #endif
-
kfree(rcu_dereference_protected(dev-ingress_queue, 1));
 
/* Flush device addresses */
-- 
1.8.3.1

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Re: [RFC 1/4] net: allow large number of rx queues

2014-08-18 Thread Sergei Shtylyov 

Hello.

On 08/18/2014 05:37 PM, Pankaj Gupta wrote:


netif_alloc_rx_queues() uses kcalloc() to allocate memory
for struct netdev_queue *_rx array.
If we are doing large rx queue allocation kcalloc() might
fail, so this patch does a fallback to vzalloc().
Similar implementation is done for tx queue allocation in
netif_alloc_netdev_queues().



We avoid failure of high order memory allocation
with the help of vzalloc(), this allows us to do large
rx and tx queue allocation which in turn helps us to
increase the number of queues in tun.



As vmalloc() adds overhead on a critical network path,
__GFP_REPEAT flag is used with kzalloc() to do this fallback
only when really needed.



Signed-off-by: Pankaj Gupta pagu...@redhat.com
Reviewed-by: Michael S. Tsirkin m...@redhat.com
Reviewed-by: David Gibson dgib...@redhat.com
---
  net/core/dev.c | 20 +---
  1 file changed, 13 insertions(+), 7 deletions(-)



diff --git a/net/core/dev.c b/net/core/dev.c
index 1c15b18..a455a02 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct 
net_device *rootdev,
  EXPORT_SYMBOL(netif_stacked_transfer_operstate);

  #ifdef CONFIG_SYSFS
+static void netif_free_rx_queues(struct net_device *dev)
+{
+   kvfree(dev-_rx);
+}
+
  static int netif_alloc_rx_queues(struct net_device *dev)
  {
unsigned int i, count = dev-num_rx_queues;
struct netdev_rx_queue *rx;
-
+   size_t sz = count * sizeof(*rx);


  Please keep an empty line after declarations.


BUG_ON(count  1);



WBR, Sergei

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Re: [RFC 1/4] net: allow large number of rx queues

2014-08-18 Thread Pankaj Gupta 

 Hello.
 
 On 08/18/2014 05:37 PM, Pankaj Gupta wrote:
 
  netif_alloc_rx_queues() uses kcalloc() to allocate memory
  for struct netdev_queue *_rx array.
  If we are doing large rx queue allocation kcalloc() might
  fail, so this patch does a fallback to vzalloc().
  Similar implementation is done for tx queue allocation in
  netif_alloc_netdev_queues().
 
  We avoid failure of high order memory allocation
  with the help of vzalloc(), this allows us to do large
  rx and tx queue allocation which in turn helps us to
  increase the number of queues in tun.
 
  As vmalloc() adds overhead on a critical network path,
  __GFP_REPEAT flag is used with kzalloc() to do this fallback
  only when really needed.
 
  Signed-off-by: Pankaj Gupta pagu...@redhat.com
  Reviewed-by: Michael S. Tsirkin m...@redhat.com
  Reviewed-by: David Gibson dgib...@redhat.com
  ---
net/core/dev.c | 20 +---
1 file changed, 13 insertions(+), 7 deletions(-)
 
  diff --git a/net/core/dev.c b/net/core/dev.c
  index 1c15b18..a455a02 100644
  --- a/net/core/dev.c
  +++ b/net/core/dev.c
  @@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct
  net_device *rootdev,
EXPORT_SYMBOL(netif_stacked_transfer_operstate);
 
#ifdef CONFIG_SYSFS
  +static void netif_free_rx_queues(struct net_device *dev)
  +{
  +   kvfree(dev-_rx);
  +}
  +
static int netif_alloc_rx_queues(struct net_device *dev)
{
  unsigned int i, count = dev-num_rx_queues;
  struct netdev_rx_queue *rx;
  -
  +   size_t sz = count * sizeof(*rx);
 
Please keep an empty line after declarations.
 Yes, I will add it. Thanks
 
  BUG_ON(count  1);
 
 
 WBR, Sergei
 
 
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