First user of the SKB bulk free API (namely kfree_skb_bulk() via
waitlist helper add-and-flush API).
There is an opportunity to bulk free SKBs during reclaiming of
resources after DMA transmit completes in ixgbe_clean_tx_irq. Thus,
bulk freeing at this point does not introduce any added latency.
Choosing bulk size 32 even-though budget usually is 64, due (1) to
limit the stack usage and (2) as SLAB behind SKBs have 32 objects per
slab.
Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 463ff47200f1..d35d6b47bae2 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1075,6 +1075,7 @@ static void ixgbe_tx_timeout_reset(struct ixgbe_adapter *adapter)
* @q_vector: structure containing interrupt and ring information
* @tx_ring: tx ring to clean
**/
+#define BULK_FREE_SIZE 32
static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector,
struct ixgbe_ring *tx_ring)
{
@@ -1084,6 +1085,11 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector,
unsigned int total_bytes = 0, total_packets = 0;
unsigned int budget = q_vector->tx.work_limit;
unsigned int i = tx_ring->next_to_clean;
+ struct sk_buff *skbs[BULK_FREE_SIZE];
+ struct dev_free_waitlist wl;
+
+ wl.skb_cnt = 0;
+ wl.skbs = skbs;
if (test_bit(__IXGBE_DOWN, &adapter->state))
return true;
@@ -1113,8 +1119,8 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector,
total_bytes += tx_buffer->bytecount;
total_packets += tx_buffer->gso_segs;
- /* free the skb */
- dev_consume_skb_any(tx_buffer->skb);
+ /* delay skb free and bulk free later */
+ dev_free_waitlist_add(&wl, tx_buffer->skb, BULK_FREE_SIZE);
/* unmap skb header data */
dma_unmap_single(tx_ring->dev,
@@ -1164,6 +1170,8 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector,
budget--;
} while (likely(budget));
+ dev_free_waitlist_flush(&wl); /* free remaining SKBs on waitlist */
+
i += tx_ring->count;
tx_ring->next_to_clean = i;
u64_stats_update_begin(&tx_ring->syncp);
@@ -1224,6 +1232,7 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector,
return !!budget;
}
+#undef BULK_FREE_SIZE
#ifdef CONFIG_IXGBE_DCA
static void ixgbe_update_tx_dca(struct ixgbe_adapter *adapter,
--
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