svn commit: r294030 - stable/10/sys/dev/e1000

[Sean Bruno]

Author: sbruno
Date: Thu Jan 14 18:57:17 2016
New Revision: 294030
URL: https://svnweb.freebsd.org/changeset/base/294030

Log:
  MFC r292670
  
  Add support for sysctl knobs to live tune the tx packet processing limits
  in igb and fix a wrap-around bug.
  
  Submitted by:	Jason (j at nitrology.com)
  Sponsored by:	Limelight Networks

Modified:
  stable/10/sys/dev/e1000/if_igb.c
  stable/10/sys/dev/e1000/if_igb.h
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/e1000/if_igb.c
==============================================================================
--- stable/10/sys/dev/e1000/if_igb.c	Thu Jan 14 18:53:54 2016	(r294029)
+++ stable/10/sys/dev/e1000/if_igb.c	Thu Jan 14 18:57:17 2016	(r294030)
@@ -408,6 +408,13 @@ SYSCTL_INT(_hw_igb, OID_AUTO, rx_process
     &igb_rx_process_limit, 0,
     "Maximum number of received packets to process at a time, -1 means unlimited");
 
+/* How many packets txeof tries to clean at a time */
+static int igb_tx_process_limit = -1;
+TUNABLE_INT("hw.igb.tx_process_limit", &igb_tx_process_limit);
+SYSCTL_INT(_hw_igb, OID_AUTO, tx_process_limit, CTLFLAG_RDTUN,
+    &igb_tx_process_limit, 0,
+    "Maximum number of sent packets to process at a time, -1 means unlimited");
+
 #ifdef DEV_NETMAP	/* see ixgbe.c for details */
 #include <dev/netmap/if_igb_netmap.h>
 #endif /* DEV_NETMAP */
@@ -526,11 +533,15 @@ igb_attach(device_t dev)
 
 	e1000_get_bus_info(&adapter->hw);
 
-	/* Sysctl for limiting the amount of work done in the taskqueue */
+	/* Sysctls for limiting the amount of work done in the taskqueues */
 	igb_set_sysctl_value(adapter, "rx_processing_limit",
 	    "max number of rx packets to process",
 	    &adapter->rx_process_limit, igb_rx_process_limit);
 
+	igb_set_sysctl_value(adapter, "tx_processing_limit",
+	    "max number of tx packets to process",
+	    &adapter->tx_process_limit, igb_tx_process_limit);
+
 	/*
 	 * Validate number of transmit and receive descriptors. It
 	 * must not exceed hardware maximum, and must be multiple
@@ -3956,7 +3967,7 @@ igb_txeof(struct tx_ring *txr)
 	struct adapter		*adapter = txr->adapter;
 	struct ifnet		*ifp = adapter->ifp;
 	u32			work, processed = 0;
-	u16			limit = txr->process_limit;
+	int			limit = adapter->tx_process_limit;
 	struct igb_tx_buf	*buf;
 	union e1000_adv_tx_desc *txd;
 

Modified: stable/10/sys/dev/e1000/if_igb.h
==============================================================================
--- stable/10/sys/dev/e1000/if_igb.h	Thu Jan 14 18:53:54 2016	(r294029)
+++ stable/10/sys/dev/e1000/if_igb.h	Thu Jan 14 18:57:17 2016	(r294030)
@@ -300,7 +300,6 @@ struct tx_ring {
 	volatile u16		tx_avail;
 	u16			next_avail_desc;
 	u16			next_to_clean;
-	u16			process_limit;
 	u16			num_desc;
 	enum {
 	    IGB_QUEUE_IDLE = 1,
@@ -479,6 +478,7 @@ struct adapter {
 	int			has_manage;
 	int			wol;
 	int			rx_process_limit;
+	int			tx_process_limit;
 	u16			vf_ifp;  /* a VF interface */
 	bool			in_detach; /* Used only in igb_ioctl */