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Message-ID: <20090424054557.GA24575@gondor.apana.org.au>
Date: Fri, 24 Apr 2009 13:45:57 +0800
From: Herbert Xu <herbert@...dor.apana.org.au>
To: Andrew Gallatin <gallatin@...i.com>
Cc: David Miller <davem@...emloft.net>, brice@...i.com,
sgruszka@...hat.com, netdev@...r.kernel.org
Subject: Re: [PATCH] myr10ge: again fix lro_gen_skb() alignment
On Wed, Apr 22, 2009 at 11:37:24AM -0400, Andrew Gallatin wrote:
>
> I booted the sender into a kernel.org 2.6.18.2 so as to try to have
> results as close to yours as possible (I was running 2.6.22 on the
> sender before).
OK I've got my hands on a myricom card. I've tested it using the
same 2.6.18 sender that I used against the eariler cxgb3 test.
I wasn't able to discern any significant deviations between LRO
and GRO.
Unfortunately it seems that this machine is a little too fast
so even with the IRQ bound to a single CPU it's way overspeced
for 10GbE:
Idle at 10Gb IRQ rate soaker IRQ rate soaker throuput
GRO 43-45 14700 13300 7933
LRO 43-45 14700 13300 7943
But even with the soaker running they seem to be neck and neck.
Here's the patch I used BTW. I got the checksums to work by
just setting skb->csum.
diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index f2c4a66..91de78f 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -48,7 +48,6 @@
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
-#include <linux/inet_lro.h>
#include <linux/dca.h>
#include <linux/ip.h>
#include <linux/inet.h>
@@ -92,7 +91,6 @@ MODULE_LICENSE("Dual BSD/GPL");
#define MYRI10GE_EEPROM_STRINGS_SIZE 256
#define MYRI10GE_MAX_SEND_DESC_TSO ((65536 / 2048) * 2)
-#define MYRI10GE_MAX_LRO_DESCRIPTORS 8
#define MYRI10GE_LRO_MAX_PKTS 64
#define MYRI10GE_NO_CONFIRM_DATA htonl(0xffffffff)
@@ -161,8 +159,6 @@ struct myri10ge_rx_done {
dma_addr_t bus;
int cnt;
int idx;
- struct net_lro_mgr lro_mgr;
- struct net_lro_desc lro_desc[MYRI10GE_MAX_LRO_DESCRIPTORS];
};
struct myri10ge_slice_netstats {
@@ -1264,18 +1260,31 @@ static inline int
myri10ge_rx_done(struct myri10ge_slice_state *ss, struct myri10ge_rx_buf *rx,
int bytes, int len, __wsum csum)
{
+ struct napi_struct *napi = &ss->napi;
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 skb_frag_struct *rx_frags;
+ int i, idx, remainder;
struct pci_dev *pdev = mgp->pdev;
- struct net_device *dev = mgp->dev;
u8 *va;
len += MXGEFW_PAD;
idx = rx->cnt & rx->mask;
va = page_address(rx->info[idx].page) + rx->info[idx].page_offset;
prefetch(va);
+
+ skb = napi_get_frags(napi);
+ if ((unlikely(!skb))) {
+ for (i = 0, remainder = len; remainder > 0; i++) {
+ myri10ge_unmap_rx_page(pdev, &rx->info[idx], bytes);
+ put_page(rx->info[idx].page);
+ rx->cnt++;
+ idx = rx->cnt & rx->mask;
+ remainder -= MYRI10GE_ALLOC_SIZE;
+ }
+ }
+ rx_frags = skb_shinfo(skb)->frags;
+
/* Fill skb_frag_struct(s) with data from our receive */
for (i = 0, remainder = len; remainder > 0; i++) {
myri10ge_unmap_rx_page(pdev, &rx->info[idx], bytes);
@@ -1290,52 +1299,18 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, struct myri10ge_rx_buf *rx,
remainder -= MYRI10GE_ALLOC_SIZE;
}
- if (mgp->csum_flag && myri10ge_lro) {
- rx_frags[0].page_offset += MXGEFW_PAD;
- rx_frags[0].size -= MXGEFW_PAD;
- len -= MXGEFW_PAD;
- lro_receive_frags(&ss->rx_done.lro_mgr, rx_frags,
- /* opaque, will come back in get_frag_header */
- len, len,
- (void *)(__force unsigned long)csum, csum);
-
- return 1;
- }
-
- hlen = MYRI10GE_HLEN > len ? len : MYRI10GE_HLEN;
-
- /* allocate an skb to attach the page(s) to. This is done
- * after trying LRO, so as to avoid skb allocation overheads */
-
- skb = netdev_alloc_skb(dev, MYRI10GE_HLEN + 16);
- if (unlikely(skb == NULL)) {
- ss->stats.rx_dropped++;
- do {
- i--;
- put_page(rx_frags[i].page);
- } while (i != 0);
- return 0;
- }
-
- /* Attach the pages to the skb, and trim off any padding */
- myri10ge_rx_skb_build(skb, va, rx_frags, len, hlen);
- if (skb_shinfo(skb)->frags[0].size <= 0) {
- put_page(skb_shinfo(skb)->frags[0].page);
- skb_shinfo(skb)->nr_frags = 0;
- }
- skb->protocol = eth_type_trans(skb, dev);
- skb_record_rx_queue(skb, ss - &mgp->ss[0]);
-
- if (mgp->csum_flag) {
- if ((skb->protocol == htons(ETH_P_IP)) ||
- (skb->protocol == htons(ETH_P_IPV6))) {
- skb->csum = csum;
- skb->ip_summed = CHECKSUM_COMPLETE;
- } else
- myri10ge_vlan_ip_csum(skb, csum);
- }
- netif_receive_skb(skb);
+ rx_frags[0].page_offset += MXGEFW_PAD;
+ rx_frags[0].size -= MXGEFW_PAD;
+ len -= MXGEFW_PAD;
+ skb_shinfo(skb)->nr_frags = i;
+ skb->len = len;
+ skb->data_len = len;
+ skb->truesize += len;
+ skb->csum = csum;
+ skb->ip_summed = CHECKSUM_COMPLETE;
+ napi_gro_frags(napi);
return 1;
+
}
static inline void
@@ -1445,9 +1420,6 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
ss->stats.rx_packets += rx_packets;
ss->stats.rx_bytes += rx_bytes;
- if (myri10ge_lro)
- lro_flush_all(&rx_done->lro_mgr);
-
/* restock receive rings if needed */
if (ss->rx_small.fill_cnt - ss->rx_small.cnt < myri10ge_fill_thresh)
myri10ge_alloc_rx_pages(mgp, &ss->rx_small,
@@ -1752,9 +1724,7 @@ static const char myri10ge_gstrings_slice_stats[][ETH_GSTRING_LEN] = {
"----------- slice ---------",
"tx_pkt_start", "tx_pkt_done", "tx_req", "tx_done",
"rx_small_cnt", "rx_big_cnt",
- "wake_queue", "stop_queue", "tx_linearized", "LRO aggregated",
- "LRO flushed",
- "LRO avg aggr", "LRO no_desc"
+ "wake_queue", "stop_queue", "tx_linearized"
};
#define MYRI10GE_NET_STATS_LEN 21
@@ -1851,14 +1821,6 @@ myri10ge_get_ethtool_stats(struct net_device *netdev,
data[i++] = (unsigned int)ss->tx.wake_queue;
data[i++] = (unsigned int)ss->tx.stop_queue;
data[i++] = (unsigned int)ss->tx.linearized;
- data[i++] = ss->rx_done.lro_mgr.stats.aggregated;
- data[i++] = ss->rx_done.lro_mgr.stats.flushed;
- if (ss->rx_done.lro_mgr.stats.flushed)
- data[i++] = ss->rx_done.lro_mgr.stats.aggregated /
- ss->rx_done.lro_mgr.stats.flushed;
- else
- data[i++] = 0;
- data[i++] = ss->rx_done.lro_mgr.stats.no_desc;
}
}
@@ -2186,67 +2148,6 @@ static void myri10ge_free_irq(struct myri10ge_priv *mgp)
pci_disable_msix(pdev);
}
-static int
-myri10ge_get_frag_header(struct skb_frag_struct *frag, void **mac_hdr,
- void **ip_hdr, void **tcpudp_hdr,
- u64 * hdr_flags, void *priv)
-{
- struct ethhdr *eh;
- struct vlan_ethhdr *veh;
- struct iphdr *iph;
- u8 *va = page_address(frag->page) + frag->page_offset;
- unsigned long ll_hlen;
- /* passed opaque through lro_receive_frags() */
- __wsum csum = (__force __wsum) (unsigned long)priv;
-
- /* find the mac header, aborting if not IPv4 */
-
- eh = (struct ethhdr *)va;
- *mac_hdr = eh;
- ll_hlen = ETH_HLEN;
- if (eh->h_proto != htons(ETH_P_IP)) {
- if (eh->h_proto == htons(ETH_P_8021Q)) {
- veh = (struct vlan_ethhdr *)va;
- if (veh->h_vlan_encapsulated_proto != htons(ETH_P_IP))
- return -1;
-
- ll_hlen += VLAN_HLEN;
-
- /*
- * HW checksum starts ETH_HLEN bytes into
- * frame, so we must subtract off the VLAN
- * header's checksum before csum can be used
- */
- csum = csum_sub(csum, csum_partial(va + ETH_HLEN,
- VLAN_HLEN, 0));
- } else {
- return -1;
- }
- }
- *hdr_flags = LRO_IPV4;
-
- iph = (struct iphdr *)(va + ll_hlen);
- *ip_hdr = iph;
- if (iph->protocol != IPPROTO_TCP)
- return -1;
- if (iph->frag_off & htons(IP_MF | IP_OFFSET))
- return -1;
- *hdr_flags |= LRO_TCP;
- *tcpudp_hdr = (u8 *) (*ip_hdr) + (iph->ihl << 2);
-
- /* verify the IP checksum */
- if (unlikely(ip_fast_csum((u8 *) iph, iph->ihl)))
- return -1;
-
- /* verify the checksum */
- if (unlikely(csum_tcpudp_magic(iph->saddr, iph->daddr,
- ntohs(iph->tot_len) - (iph->ihl << 2),
- IPPROTO_TCP, csum)))
- return -1;
-
- return 0;
-}
-
static int myri10ge_get_txrx(struct myri10ge_priv *mgp, int slice)
{
struct myri10ge_cmd cmd;
@@ -2317,7 +2218,6 @@ static int myri10ge_open(struct net_device *dev)
struct myri10ge_cmd cmd;
int i, status, big_pow2, slice;
u8 *itable;
- struct net_lro_mgr *lro_mgr;
if (mgp->running != MYRI10GE_ETH_STOPPED)
return -EBUSY;
@@ -2438,19 +2338,6 @@ static int myri10ge_open(struct net_device *dev)
goto abort_with_rings;
}
- lro_mgr = &ss->rx_done.lro_mgr;
- lro_mgr->dev = dev;
- lro_mgr->features = LRO_F_NAPI;
- lro_mgr->ip_summed = CHECKSUM_COMPLETE;
- lro_mgr->ip_summed_aggr = CHECKSUM_UNNECESSARY;
- lro_mgr->max_desc = MYRI10GE_MAX_LRO_DESCRIPTORS;
- lro_mgr->lro_arr = ss->rx_done.lro_desc;
- lro_mgr->get_frag_header = myri10ge_get_frag_header;
- lro_mgr->max_aggr = myri10ge_lro_max_pkts;
- lro_mgr->frag_align_pad = 2;
- if (lro_mgr->max_aggr > MAX_SKB_FRAGS)
- lro_mgr->max_aggr = MAX_SKB_FRAGS;
-
/* must happen prior to any irq */
napi_enable(&(ss)->napi);
}
@@ -3884,7 +3771,7 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
if (dac_enabled)
netdev->features |= NETIF_F_HIGHDMA;
-
+ netdev->features |= NETIF_F_GRO;
/* make sure we can get an irq, and that MSI can be
* setup (if available). Also ensure netdev->irq
* is set to correct value if MSI is enabled */
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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