diff mbox

[3/4] sfc: Feed GRO result into RX allocation policy and interrupt moderation

Message ID 1256836884.2827.73.camel@achroite
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Ben Hutchings Oct. 29, 2009, 5:21 p.m. UTC 
When GRO is successfully merging received packets, we should allocate
raw page buffers rather than skbs that will be discarded by GRO.
Otherwise, we should allocate skbs.

GRO also benefits from higher interrupt moderation, so increase the
score for mergeable RX packets.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/net/sfc/rx.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

Comments

David Miller Oct. 30, 2009, 4:33 a.m. UTC | #1 
From: Ben Hutchings <bhutchings@solarflare.com>
Date: Thu, 29 Oct 2009 17:21:24 +0000

> When GRO is successfully merging received packets, we should allocate
> raw page buffers rather than skbs that will be discarded by GRO.
> Otherwise, we should allocate skbs.
> 
> GRO also benefits from higher interrupt moderation, so increase the
> score for mergeable RX packets.
> 
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

I'll pull net-2.6 into net-next-2.6 before applying this patch and the
next one.

But you need to tell me that such dependencies exist when you submit
patches like this, ok?
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diff mbox

Patch

diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
index 4b65c62..9277e9a 100644
--- a/drivers/net/sfc/rx.c
+++ b/drivers/net/sfc/rx.c
@@ -445,6 +445,7 @@  static void efx_rx_packet_lro(struct efx_channel *channel,
 			      bool checksummed)
 {
 	struct napi_struct *napi = &channel->napi_str;
+	gro_result_t gro_result;
 
 	/* Pass the skb/page into the LRO engine */
 	if (rx_buf->page) {
@@ -452,6 +453,7 @@  static void efx_rx_packet_lro(struct efx_channel *channel,
 
 		if (!skb) {
 			put_page(rx_buf->page);
+			gro_result = GRO_DROP;
 			goto out;
 		}
 
@@ -467,7 +469,7 @@  static void efx_rx_packet_lro(struct efx_channel *channel,
 		skb->ip_summed =
 			checksummed ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
 
-		napi_gro_frags(napi);
+		gro_result = napi_gro_frags(napi);
 
 out:
 		EFX_BUG_ON_PARANOID(rx_buf->skb);
@@ -476,9 +478,16 @@  out:
 		EFX_BUG_ON_PARANOID(!rx_buf->skb);
 		EFX_BUG_ON_PARANOID(!checksummed);
 
-		napi_gro_receive(napi, rx_buf->skb);
+		gro_result = napi_gro_receive(napi, rx_buf->skb);
 		rx_buf->skb = NULL;
 	}
+
+	if (gro_result == GRO_NORMAL) {
+		channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
+	} else if (gro_result != GRO_DROP) {
+		channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;
+		channel->irq_mod_score += 2;
+	}
 }
 
 void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,