bge interrupt coalescing sysctls

[Igor Sysoev]

For a long time I used Bruce Evans' patch to tune bge interrupt coalescing:
http://lists.freebsd.org/pipermail/freebsd-net/2007-November/015956.html
However, recent commit SVN r192478 in 7-STABLE (r192127 in HEAD) had broken
the patch. I'm not sure how to fix the collision, and since I do not
use dynamic tuning I has left only static coalescing parameters in the patch
and has added a loader tunable to set number of receive descriptors and
read only sysctl to read the tunable. I usually use these parameters:

/boot/loader.conf:
hw.bge.rxd=512

/etc/sysctl.conf:
dev.bge.0.rx_coal_ticks=500
dev.bge.0.tx_coal_ticks=10000
dev.bge.0.rx_max_coal_bds=64
dev.bge.0.tx_max_coal_bds=128
# apply the above parameters
dev.bge.0.program_coal=1

Could anyone commit it ?


-- 
Igor Sysoev
http://sysoev.ru/en/
-------------- next part --------------
--- sys/dev/bge/if_bge.c	2009-05-21 01:17:10.000000000 +0400
+++ sys/dev/bge/if_bge.c	2009-06-05 13:45:49.000000000 +0400
@@ -447,12 +447,16 @@
 DRIVER_MODULE(miibus, bge, miibus_driver, miibus_devclass, 0, 0);
 
 static int bge_allow_asf = 0;
+static int bge_rxd = BGE_SSLOTS;
 
 TUNABLE_INT("hw.bge.allow_asf", &bge_allow_asf);
+TUNABLE_INT("hw.bge.rxd", &bge_rxd);
 
 SYSCTL_NODE(_hw, OID_AUTO, bge, CTLFLAG_RD, 0, "BGE driver parameters");
 SYSCTL_INT(_hw_bge, OID_AUTO, allow_asf, CTLFLAG_RD, &bge_allow_asf, 0,
 	"Allow ASF mode if available");
+SYSCTL_INT(_hw_bge, OID_AUTO, bge_rxd, CTLFLAG_RD, &bge_rxd, 0,
+	"Number of receive descriptors");
 
 #define	SPARC64_BLADE_1500_MODEL	"SUNW,Sun-Blade-1500"
 #define	SPARC64_BLADE_1500_PATH_BGE	"/pci at 1f,700000/network at 2"
@@ -1008,21 +1012,15 @@
 	return (0);
 }
 
-/*
- * The standard receive ring has 512 entries in it. At 2K per mbuf cluster,
- * that's 1MB or memory, which is a lot. For now, we fill only the first
- * 256 ring entries and hope that our CPU is fast enough to keep up with
- * the NIC.
- */
 static int
 bge_init_rx_ring_std(struct bge_softc *sc)
 {
 	int i;
 
-	for (i = 0; i < BGE_SSLOTS; i++) {
+	for (i = 0; i < bge_rxd; i++) {
 		if (bge_newbuf_std(sc, i, NULL) == ENOBUFS)
 			return (ENOBUFS);
-	};
+	}
 
 	bus_dmamap_sync(sc->bge_cdata.bge_rx_std_ring_tag,
 	    sc->bge_cdata.bge_rx_std_ring_map,
@@ -2383,6 +2381,52 @@
 #endif
 
 static int
+bge_sysctl_program_coal(SYSCTL_HANDLER_ARGS)
+{
+	struct bge_softc *sc;
+	int error, i, val;
+
+	val = 0;
+	error = sysctl_handle_int(oidp, &val, 0, req);
+	if (error != 0 || req->newptr == NULL)
+		return (error);
+        sc = arg1;
+	BGE_LOCK(sc);
+
+	/* XXX cut from bge_blockinit(): */
+
+	/* Disable host coalescing until we get it set up */
+	CSR_WRITE_4(sc, BGE_HCC_MODE, 0x00000000);
+
+	/* Poll to make sure it's shut down. */
+	for (i = 0; i < BGE_TIMEOUT; i++) {
+		if (!(CSR_READ_4(sc, BGE_HCC_MODE) & BGE_HCCMODE_ENABLE))
+			break;
+		DELAY(10);
+	}
+
+	if (i == BGE_TIMEOUT) {
+		device_printf(sc->bge_dev,
+		    "host coalescing engine failed to idle\n");
+		CSR_WRITE_4(sc, BGE_HCC_MODE, BGE_HCCMODE_ENABLE);
+		BGE_UNLOCK(sc);
+		return (ENXIO);
+	}
+
+	/* Set up host coalescing defaults */
+	CSR_WRITE_4(sc, BGE_HCC_RX_COAL_TICKS, sc->bge_rx_coal_ticks);
+	CSR_WRITE_4(sc, BGE_HCC_TX_COAL_TICKS, sc->bge_tx_coal_ticks);
+	CSR_WRITE_4(sc, BGE_HCC_RX_MAX_COAL_BDS, sc->bge_rx_max_coal_bds);
+	CSR_WRITE_4(sc, BGE_HCC_TX_MAX_COAL_BDS, sc->bge_tx_max_coal_bds);
+
+	/* Turn on host coalescing state machine */
+	CSR_WRITE_4(sc, BGE_HCC_MODE, BGE_HCCMODE_ENABLE);
+
+	BGE_UNLOCK(sc);
+	return (0);
+}
+
+static int
 bge_attach(device_t dev)
 {
 	struct ifnet *ifp;
@@ -4495,6 +4539,19 @@
 	ctx = device_get_sysctl_ctx(sc->bge_dev);
 	children = SYSCTL_CHILDREN(device_get_sysctl_tree(sc->bge_dev));
 
+	SYSCTL_ADD_PROC(ctx, children, OID_AUTO, "program_coal",
+	    CTLTYPE_INT | CTLFLAG_RW,
+	    sc, 0, bge_sysctl_program_coal, "I",
+	    "program bge coalescence values");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "rx_coal_ticks", CTLFLAG_RW,
+	    &sc->bge_rx_coal_ticks, 0, "");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "tx_coal_ticks", CTLFLAG_RW,
+	    &sc->bge_tx_coal_ticks, 0, "");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "rx_max_coal_bds", CTLFLAG_RW,
+	    &sc->bge_rx_max_coal_bds, 0, "");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "tx_max_coal_bds", CTLFLAG_RW,
+	    &sc->bge_tx_max_coal_bds, 0, "");
+
 #ifdef BGE_REGISTER_DEBUG
 	SYSCTL_ADD_PROC(ctx, children, OID_AUTO, "debug_info",
 	    CTLTYPE_INT | CTLFLAG_RW, sc, 0, bge_sysctl_debug_info, "I",