[PATCH][next][v2] iavf: use kvzalloc instead of kzalloc for rx/tx_bi buffer

[PATCH][next][v2] iavf: use kvzalloc instead of kzalloc for rx/tx_bi buffer

[Li RongQing]

when changes the rx/tx ring to 4096, kzalloc may fail due to
a temporary shortage on slab entries.

so using kvmalloc to allocate this memory as there is no need
that this memory area is physical continuously.

and using __GFP_RETRY_MAYFAIL to allocate from kmalloc as
far as possible, which can reduce TLB pressure than vmalloc
as suggested by Eric Dumazet

Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
v2: __GFP_RETRY_MAYFAIL is used

 drivers/net/ethernet/intel/iavf/iavf_txrx.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_txrx.c b/drivers/net/ethernet/intel/iavf/iavf_txrx.c
index 256fa07d54d5..e7a1e9039cee 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_txrx.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_txrx.c
@@ -92,7 +92,7 @@ void iavf_clean_tx_ring(struct iavf_ring *tx_ring)
 void iavf_free_tx_resources(struct iavf_ring *tx_ring)
 {
 	iavf_clean_tx_ring(tx_ring);
-	kfree(tx_ring->tx_bi);
+	kvfree(tx_ring->tx_bi);
 	tx_ring->tx_bi = NULL;
 
 	if (tx_ring->desc) {
@@ -622,7 +622,8 @@ int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring)
 	/* warn if we are about to overwrite the pointer */
 	WARN_ON(tx_ring->tx_bi);
 	bi_size = sizeof(struct iavf_tx_buffer) * tx_ring->count;
-	tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL);
+	tx_ring->tx_bi = kvzalloc(bi_size, GFP_KERNEL |
+					  __GFP_RETRY_MAYFAIL);
 	if (!tx_ring->tx_bi)
 		goto err;
 
@@ -643,7 +644,7 @@ int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring)
 	return 0;
 
 err:
-	kfree(tx_ring->tx_bi);
+	kvfree(tx_ring->tx_bi);
 	tx_ring->tx_bi = NULL;
 	return -ENOMEM;
 }
@@ -714,7 +715,7 @@ void iavf_clean_rx_ring(struct iavf_ring *rx_ring)
 void iavf_free_rx_resources(struct iavf_ring *rx_ring)
 {
 	iavf_clean_rx_ring(rx_ring);
-	kfree(rx_ring->rx_bi);
+	kvfree(rx_ring->rx_bi);
 	rx_ring->rx_bi = NULL;
 
 	if (rx_ring->desc) {
@@ -738,7 +739,8 @@ int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring)
 	/* warn if we are about to overwrite the pointer */
 	WARN_ON(rx_ring->rx_bi);
 	bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count;
-	rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL);
+	rx_ring->rx_bi = kvzalloc(bi_size, GFP_KERNEL |
+				      __GFP_RETRY_MAYFAIL);
 	if (!rx_ring->rx_bi)
 		goto err;
 
@@ -762,7 +764,7 @@ int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring)
 
 	return 0;
 err:
-	kfree(rx_ring->rx_bi);
+	kvfree(rx_ring->rx_bi);
 	rx_ring->rx_bi = NULL;
 	return -ENOMEM;
 }
-- 
2.16.2

Re: [PATCH][next][v2] iavf: use kvzalloc instead of kzalloc for rx/tx_bi buffer

[Jesse Brandeburg]

Li RongQing wrote:

> when changes the rx/tx ring to 4096, kzalloc may fail due to
> a temporary shortage on slab entries.
> 
> so using kvmalloc to allocate this memory as there is no need
> that this memory area is physical continuously.
> 
> and using __GFP_RETRY_MAYFAIL to allocate from kmalloc as
> far as possible, which can reduce TLB pressure than vmalloc
> as suggested by Eric Dumazet

This change is no good, it's using RETRY_MAYFAIL but still using
v*alloc.

Please see my replies to the i40e version of the patch. I don't think
we should apply these.