From: Stanislaw Gruszka <sgruszka@redhat.com>
To: netdev@vger.kernel.org
Cc: Andrew Gallatin <gallatin@myri.com>, Brice Goglin <brice@myri.com>
Subject: [RFC] myri10ge: small rx_done refactoring
Date: Wed, 23 Mar 2011 13:52:04 +0100 [thread overview]
Message-ID: <20110323124939.GA7834@redhat.com> (raw)
myri10ge: small rx_done refactoring
Add lro_enable variable to read NETIF_F_LRO flag only once per napi poll
call. This should fix theoretical race condition with
myri10ge_set_rx_csum() and myri10ge_set_flags() where flag NETIF_F_LRO
can be changed.
On the way reduce myri10ge_rx_done() number of arguments and calls by
moving mgp->small_bytes check into that function. That reduce code size
from:
text data bss dec hex filename
36644 248 100 36992 9080 drivers/net/myri10ge/myri10ge.o
to:
text data bss dec hex filename
36037 247 100 36384 8e20 drivers/net/myri10ge/myri10ge.o
on my i686 system, what should also make myri10ge_clean_rx_done()
being faster.
diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index 24386a8..2e71240 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -1312,17 +1312,26 @@ myri10ge_unmap_rx_page(struct pci_dev *pdev,
* page into an skb */
static inline int
-myri10ge_rx_done(struct myri10ge_slice_state *ss, struct myri10ge_rx_buf *rx,
- int bytes, int len, __wsum csum)
+myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum,
+ bool lro_enabled)
{
struct myri10ge_priv *mgp = ss->mgp;
struct sk_buff *skb;
struct skb_frag_struct rx_frags[MYRI10GE_MAX_FRAGS_PER_FRAME];
- int i, idx, hlen, remainder;
+ struct myri10ge_rx_buf *rx;
+ int i, idx, hlen, remainder, bytes;
struct pci_dev *pdev = mgp->pdev;
struct net_device *dev = mgp->dev;
u8 *va;
+ if (len <= mgp->small_bytes) {
+ rx = &ss->rx_small;
+ bytes = mgp->small_bytes;
+ } else {
+ rx = &ss->rx_big,
+ bytes = mgp->big_bytes;
+ }
+
len += MXGEFW_PAD;
idx = rx->cnt & rx->mask;
va = page_address(rx->info[idx].page) + rx->info[idx].page_offset;
@@ -1341,7 +1350,7 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, struct myri10ge_rx_buf *rx,
remainder -= MYRI10GE_ALLOC_SIZE;
}
- if (dev->features & NETIF_F_LRO) {
+ if (lro_enabled) {
rx_frags[0].page_offset += MXGEFW_PAD;
rx_frags[0].size -= MXGEFW_PAD;
len -= MXGEFW_PAD;
@@ -1464,6 +1473,7 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
struct myri10ge_rx_done *rx_done = &ss->rx_done;
struct myri10ge_priv *mgp = ss->mgp;
struct net_device *netdev = mgp->dev;
+ bool lro_enabled = (netdev->features & NETIF_F_LRO) ? true : false;
unsigned long rx_bytes = 0;
unsigned long rx_packets = 0;
unsigned long rx_ok;
@@ -1478,14 +1488,7 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
length = ntohs(rx_done->entry[idx].length);
rx_done->entry[idx].length = 0;
checksum = csum_unfold(rx_done->entry[idx].checksum);
- if (length <= mgp->small_bytes)
- rx_ok = myri10ge_rx_done(ss, &ss->rx_small,
- mgp->small_bytes,
- length, checksum);
- else
- rx_ok = myri10ge_rx_done(ss, &ss->rx_big,
- mgp->big_bytes,
- length, checksum);
+ rx_ok = myri10ge_rx_done(ss, length, checksum, lro_enabled);
rx_packets += rx_ok;
rx_bytes += rx_ok * (unsigned long)length;
cnt++;
@@ -1497,7 +1500,7 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
ss->stats.rx_packets += rx_packets;
ss->stats.rx_bytes += rx_bytes;
- if (netdev->features & NETIF_F_LRO)
+ if (lro_enabled)
lro_flush_all(&rx_done->lro_mgr);
/* restock receive rings if needed */
next reply other threads:[~2011-03-23 12:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-23 12:52 Stanislaw Gruszka [this message]
2011-03-23 15:21 ` [RFC] myri10ge: small rx_done refactoring Andrew Gallatin
2011-03-23 15:33 ` Stephen Hemminger
2011-03-24 8:16 ` Stanislaw Gruszka
2011-03-24 15:15 ` Stephen Hemminger
2011-03-24 15:59 ` Stanislaw Gruszka
2011-03-24 16:42 ` Ben Hutchings
2011-03-24 17:29 ` David Howells
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