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Commit 24a427cf authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
Browse files

chelsio: more rx speedup 



Cleanup receive processing some more:
   * do the reserve padding of skb during setup
   * don't pass constants to get_packet
   * do smart prefetch of skb
   * make copybreak a module parameter

Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 3de00b89

drivers/net/chelsio/sge.c

+45 −42
Original line number Diff line number Diff line
@@ -71,12 +71,9 @@ 
#define SGE_FREEL_REFILL_THRESH	16

#define SGE_RESPQ_E_N		1024

#define SGE_INTRTIMER_NRES	1000

#define SGE_RX_COPY_THRES	256

#define SGE_RX_SM_BUF_SIZE	1536

#define SGE_TX_DESC_MAX_PLEN	16384



# define SGE_RX_DROP_THRES 2



#define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)



/*
@@ -846,6 +843,8 @@ static void refill_free_list(struct sge *sge, struct freelQ *q) 
		skb_reserve(skb, q->dma_offset);

		mapping = pci_map_single(pdev, skb->data, dma_len,

					 PCI_DMA_FROMDEVICE);

		skb_reserve(skb, sge->rx_pkt_pad);



		ce->skb = skb;

		pci_unmap_addr_set(ce, dma_addr, mapping);

		pci_unmap_len_set(ce, dma_len, dma_len);
@@ -1024,6 +1023,10 @@ static void recycle_fl_buf(struct freelQ *fl, int idx) 
	}

}



static int copybreak __read_mostly = 256;

module_param(copybreak, int, 0);

MODULE_PARM_DESC(copybreak, "Receive copy threshold");



/**

 *	get_packet - return the next ingress packet buffer

 *	@pdev: the PCI device that received the packet
@@ -1043,45 +1046,42 @@ static void recycle_fl_buf(struct freelQ *fl, int idx) 
 *	be copied but there is no memory for the copy.

 */

static inline struct sk_buff *get_packet(struct pci_dev *pdev,

					 struct freelQ *fl, unsigned int len,

					 int dma_pad, int skb_pad,

					 unsigned int copy_thres,

					 unsigned int drop_thres)

					 struct freelQ *fl, unsigned int len)

{

	struct sk_buff *skb;

	struct freelQ_ce *ce = &fl->centries[fl->cidx];

	const struct freelQ_ce *ce = &fl->centries[fl->cidx];



	if (len < copybreak) {

		skb = alloc_skb(len + 2, GFP_ATOMIC);

		if (!skb)

			goto use_orig_buf;



	if (len < copy_thres) {

		skb = alloc_skb(len + skb_pad, GFP_ATOMIC);

		if (likely(skb != NULL)) {

			skb_reserve(skb, skb_pad);

		skb_reserve(skb, 2);	/* align IP header */

		skb_put(skb, len);

		pci_dma_sync_single_for_cpu(pdev,

					    pci_unmap_addr(ce, dma_addr),

					    pci_unmap_len(ce, dma_len),

					    PCI_DMA_FROMDEVICE);

			memcpy(skb->data, ce->skb->data + dma_pad, len);

		memcpy(skb->data, ce->skb->data, len);

		pci_dma_sync_single_for_device(pdev,

					       pci_unmap_addr(ce, dma_addr),

					       pci_unmap_len(ce, dma_len),

					       PCI_DMA_FROMDEVICE);

		} else if (!drop_thres)

			goto use_orig_buf;



		recycle_fl_buf(fl, fl->cidx);

		return skb;

	}



	if (fl->credits < drop_thres) {

use_orig_buf:

	if (fl->credits < 2) {

		recycle_fl_buf(fl, fl->cidx);

		return NULL;

	}



use_orig_buf:

	pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),

			 pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);

	skb = ce->skb;

	skb_reserve(skb, dma_pad);

	prefetch(skb->data);



	skb_put(skb, len);

	return skb;

}
@@ -1359,27 +1359,25 @@ static void restart_sched(unsigned long arg) 
 *

 *	Process an ingress ethernet pakcet and deliver it to the stack.

 */

static int sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)

static void sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)

{

	struct sk_buff *skb;

	struct cpl_rx_pkt *p;

	const struct cpl_rx_pkt *p;

	struct adapter *adapter = sge->adapter;

	struct sge_port_stats *st;



	skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad,

			 sge->rx_pkt_pad, 2, SGE_RX_COPY_THRES,

			 SGE_RX_DROP_THRES);

	skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad);

	if (unlikely(!skb)) {

		sge->stats.rx_drops++;

		return 0;

		return;

	}



	p = (struct cpl_rx_pkt *)skb->data;

	skb_pull(skb, sizeof(*p));

	p = (const struct cpl_rx_pkt *) skb->data;

	if (p->iff >= adapter->params.nports) {

		kfree_skb(skb);

		return 0;

		return;

	}

	__skb_pull(skb, sizeof(*p));



	skb->dev = adapter->port[p->iff].dev;

	skb->dev->last_rx = jiffies;
@@ -1411,7 +1409,6 @@ static int sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len) 
		netif_rx(skb);

#endif

	}

	return 0;

}



/*
@@ -1493,12 +1490,11 @@ static int process_responses(struct adapter *adapter, int budget) 
	struct sge *sge = adapter->sge;

	struct respQ *q = &sge->respQ;

	struct respQ_e *e = &q->entries[q->cidx];

	int budget_left = budget;

	int done = 0;

	unsigned int flags = 0;

	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};





	while (likely(budget_left && e->GenerationBit == q->genbit)) {

	while (done < budget && e->GenerationBit == q->genbit) {

		flags |= e->Qsleeping;



		cmdq_processed[0] += e->Cmdq0CreditReturn;
@@ -1508,14 +1504,16 @@ static int process_responses(struct adapter *adapter, int budget) 
		 * ping-pong of TX state information on MP where the sender

		 * might run on a different CPU than this function...

		 */

		if (unlikely(flags & F_CMDQ0_ENABLE || cmdq_processed[0] > 64)) {

		if (unlikely((flags & F_CMDQ0_ENABLE) || cmdq_processed[0] > 64)) {

			flags = update_tx_info(adapter, flags, cmdq_processed[0]);

			cmdq_processed[0] = 0;

		}



		if (unlikely(cmdq_processed[1] > 16)) {

			sge->cmdQ[1].processed += cmdq_processed[1];

			cmdq_processed[1] = 0;

		}



		if (likely(e->DataValid)) {

			struct freelQ *fl = &sge->freelQ[e->FreelistQid];
@@ -1525,12 +1523,16 @@ static int process_responses(struct adapter *adapter, int budget) 
			else

				sge_rx(sge, fl, e->BufferLength);



			++done;



			/*

			 * Note: this depends on each packet consuming a

			 * single free-list buffer; cf. the BUG above.

			 */

			if (++fl->cidx == fl->size)

				fl->cidx = 0;

			prefetch(fl->centries[fl->cidx].skb);



			if (unlikely(--fl->credits <

				     fl->size - SGE_FREEL_REFILL_THRESH))

				refill_free_list(sge, fl);
@@ -1549,14 +1551,12 @@ static int process_responses(struct adapter *adapter, int budget) 
			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);

			q->credits = 0;

		}

		--budget_left;

	}



	flags = update_tx_info(adapter, flags, cmdq_processed[0]);

	sge->cmdQ[1].processed += cmdq_processed[1];



	budget -= budget_left;

	return budget;

	return done;

}



static inline int responses_pending(const struct adapter *adapter)
@@ -1581,11 +1581,14 @@ static int process_pure_responses(struct adapter *adapter) 
	struct sge *sge = adapter->sge;

	struct respQ *q = &sge->respQ;

	struct respQ_e *e = &q->entries[q->cidx];

	const struct freelQ *fl = &sge->freelQ[e->FreelistQid];

	unsigned int flags = 0;

	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};



	prefetch(fl->centries[fl->cidx].skb);

	if (e->DataValid)

		return 1;



	do {

		flags |= e->Qsleeping;