From 0d613a27cc753bfacd20e6eaa2183bb7fef4c76e Mon Sep 17 00:00:00 2001 From: Frank Pavlic Date: Tue, 7 Feb 2006 17:04:36 +0100 Subject: [PATCH] [PATCH] s390: lcs performance enhancements [patch 1/2] s390: lcs performance enhancements From: Klaus Wacker - When flood pinging (with large packet size) an LCS device, about 90 % of all packets are dropped by driver. - increased number of lcs IO buffers to 32. - use netif_stop_queue/netif_wake_queue in lcs_start_xmit routine - don't lock the whole xmit routine but just the piece of code where tx_buffer is touched. Signed-off-by: Frank Pavlic diffstat: lcs.c | 31 +++++++++++++++++-------------- lcs.h | 2 +- 2 files changed, 18 insertions(+), 15 deletions(-) Signed-off-by: Jeff Garzik --- drivers/s390/net/lcs.c | 31 +++++++++++++++++-------------- drivers/s390/net/lcs.h | 2 +- 2 files changed, 18 insertions(+), 15 deletions(-) diff --git a/drivers/s390/net/lcs.c b/drivers/s390/net/lcs.c index 6229ba4995..9cf88d7201 100644 --- a/drivers/s390/net/lcs.c +++ b/drivers/s390/net/lcs.c @@ -98,9 +98,9 @@ lcs_register_debug_facility(void) return -ENOMEM; } debug_register_view(lcs_dbf_setup, &debug_hex_ascii_view); - debug_set_level(lcs_dbf_setup, 4); + debug_set_level(lcs_dbf_setup, 2); debug_register_view(lcs_dbf_trace, &debug_hex_ascii_view); - debug_set_level(lcs_dbf_trace, 4); + debug_set_level(lcs_dbf_trace, 2); return 0; } @@ -1292,9 +1292,8 @@ lcs_set_multicast_list(struct net_device *dev) LCS_DBF_TEXT(4, trace, "setmulti"); card = (struct lcs_card *) dev->priv; - if (!lcs_set_thread_start_bit(card, LCS_SET_MC_THREAD)) { + if (!lcs_set_thread_start_bit(card, LCS_SET_MC_THREAD)) schedule_work(&card->kernel_thread_starter); - } } #endif /* CONFIG_IP_MULTICAST */ @@ -1459,6 +1458,8 @@ lcs_txbuffer_cb(struct lcs_channel *channel, struct lcs_buffer *buffer) lcs_release_buffer(channel, buffer); card = (struct lcs_card *) ((char *) channel - offsetof(struct lcs_card, write)); + if (netif_queue_stopped(card->dev)) + netif_wake_queue(card->dev); spin_lock(&card->lock); card->tx_emitted--; if (card->tx_emitted <= 0 && card->tx_buffer != NULL) @@ -1478,6 +1479,7 @@ __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, struct net_device *dev) { struct lcs_header *header; + int rc = 0; LCS_DBF_TEXT(5, trace, "hardxmit"); if (skb == NULL) { @@ -1492,10 +1494,8 @@ __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, card->stats.tx_carrier_errors++; return 0; } - if (netif_queue_stopped(dev) ) { - card->stats.tx_dropped++; - return -EBUSY; - } + netif_stop_queue(card->dev); + spin_lock(&card->lock); if (card->tx_buffer != NULL && card->tx_buffer->count + sizeof(struct lcs_header) + skb->len + sizeof(u16) > LCS_IOBUFFERSIZE) @@ -1506,7 +1506,8 @@ __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, card->tx_buffer = lcs_get_buffer(&card->write); if (card->tx_buffer == NULL) { card->stats.tx_dropped++; - return -EBUSY; + rc = -EBUSY; + goto out; } card->tx_buffer->callback = lcs_txbuffer_cb; card->tx_buffer->count = 0; @@ -1518,13 +1519,18 @@ __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, header->type = card->lan_type; header->slot = card->portno; memcpy(header + 1, skb->data, skb->len); + spin_unlock(&card->lock); card->stats.tx_bytes += skb->len; card->stats.tx_packets++; dev_kfree_skb(skb); - if (card->tx_emitted <= 0) + netif_wake_queue(card->dev); + spin_lock(&card->lock); + if (card->tx_emitted <= 0 && card->tx_buffer != NULL) /* If this is the first tx buffer emit it immediately. */ __lcs_emit_txbuffer(card); - return 0; +out: + spin_unlock(&card->lock); + return rc; } static int @@ -1535,9 +1541,7 @@ lcs_start_xmit(struct sk_buff *skb, struct net_device *dev) LCS_DBF_TEXT(5, trace, "pktxmit"); card = (struct lcs_card *) dev->priv; - spin_lock(&card->lock); rc = __lcs_start_xmit(card, skb, dev); - spin_unlock(&card->lock); return rc; } @@ -2319,7 +2323,6 @@ __init lcs_init_module(void) PRINT_ERR("Initialization failed\n"); return rc; } - return 0; } diff --git a/drivers/s390/net/lcs.h b/drivers/s390/net/lcs.h index 08e60ad439..2fad5e40c2 100644 --- a/drivers/s390/net/lcs.h +++ b/drivers/s390/net/lcs.h @@ -95,7 +95,7 @@ do { \ */ #define LCS_ILLEGAL_OFFSET 0xffff #define LCS_IOBUFFERSIZE 0x5000 -#define LCS_NUM_BUFFS 8 /* needs to be power of 2 */ +#define LCS_NUM_BUFFS 32 /* needs to be power of 2 */ #define LCS_MAC_LENGTH 6 #define LCS_INVALID_PORT_NO -1 #define LCS_LANCMD_TIMEOUT_DEFAULT 5 -- 2.39.5