Revert "igb: reduce CPU0 latency when updating statistics"

This reverts commit 59361316afcb08569af21e1af83e89c7051c055a.

Due to problems found in additional testing, this causes an illegal
context switch in the RCU read-side critical section.

CC: Dave Jones <davej@codemonkey.org.uk>
CC: Cong Wang <xiyou.wangcong@gmail.com>
CC: Jan Jablonsky <jan.jablonsky@thalesgroup.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index fe1592ae87690bd3c22e82527d5dc50c0197d820..ca54e268d157bd9afb7ab23854a8ae52ff260215 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -515,7 +515,7 @@ struct igb_adapter {
        /* OS defined structs */
        struct pci_dev *pdev;
 
-       struct mutex stats64_lock;
+       spinlock_t stats64_lock;
        struct rtnl_link_stats64 stats64;
 
        /* structs defined in e1000_hw.h */

diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 7426060b678fd3075bef3812ff5b9aa9c1653aaa..c5767106824521a2e78374310cbe5f15ecc4d125 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -2295,7 +2295,7 @@ static void igb_get_ethtool_stats(struct net_device *netdev,
        int i, j;
        char *p;
 
-       mutex_lock(&adapter->stats64_lock);
+       spin_lock(&adapter->stats64_lock);
        igb_update_stats(adapter);
 
        for (i = 0; i < IGB_GLOBAL_STATS_LEN; i++) {
@@ -2338,7 +2338,7 @@ static void igb_get_ethtool_stats(struct net_device *netdev,
                } while (u64_stats_fetch_retry_irq(&ring->rx_syncp, start));
                i += IGB_RX_QUEUE_STATS_LEN;
        }
-       mutex_unlock(&adapter->stats64_lock);
+       spin_unlock(&adapter->stats64_lock);
 }
 
 static void igb_get_strings(struct net_device *netdev, u32 stringset, u8 *data)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 87bdf1604ae2c5933e18827a0a7d5ad02942b936..7137e7f9c7f3c7d17a6123e7a83234f58a886e82 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2203,9 +2203,9 @@ void igb_down(struct igb_adapter *adapter)
        del_timer_sync(&adapter->phy_info_timer);
 
        /* record the stats before reset*/
-       mutex_lock(&adapter->stats64_lock);
+       spin_lock(&adapter->stats64_lock);
        igb_update_stats(adapter);
-       mutex_unlock(&adapter->stats64_lock);
+       spin_unlock(&adapter->stats64_lock);
 
        adapter->link_speed = 0;
        adapter->link_duplex = 0;
@@ -3840,7 +3840,7 @@ static int igb_sw_init(struct igb_adapter *adapter)
        adapter->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;
 
        spin_lock_init(&adapter->nfc_lock);
-       mutex_init(&adapter->stats64_lock);
+       spin_lock_init(&adapter->stats64_lock);
 #ifdef CONFIG_PCI_IOV
        switch (hw->mac.type) {
        case e1000_82576:
@@ -5406,9 +5406,9 @@ no_wait:
                }
        }
 
-       mutex_lock(&adapter->stats64_lock);
+       spin_lock(&adapter->stats64_lock);
        igb_update_stats(adapter);
-       mutex_unlock(&adapter->stats64_lock);
+       spin_unlock(&adapter->stats64_lock);
 
        for (i = 0; i < adapter->num_tx_queues; i++) {
                struct igb_ring *tx_ring = adapter->tx_ring[i];
@@ -6235,10 +6235,10 @@ static void igb_get_stats64(struct net_device *netdev,
 {
        struct igb_adapter *adapter = netdev_priv(netdev);
 
-       mutex_lock(&adapter->stats64_lock);
+       spin_lock(&adapter->stats64_lock);
        igb_update_stats(adapter);
        memcpy(stats, &adapter->stats64, sizeof(*stats));
-       mutex_unlock(&adapter->stats64_lock);
+       spin_unlock(&adapter->stats64_lock);
 }
 
 /**