svn commit: r271504 - in head/sys: dev/oce dev/vmware/vmxnet3 dev/xen/netfront net netinet ofed/drivers/net/mlx4
Adrian Chadd
adrian at freebsd.org
Sat Sep 13 16:54:43 UTC 2014
Hi,
Just for the record:
* I'm glad you're tackling the TSO config stuff;
* I'm not glad you're trying to pack it into a u_int rather than
creating a new structure and adding fields for it.
I appreciate that you're trying to rush this in before 10.1, but this
is exactly why things shouldn't be rushed in before release deadlines.
:)
I'd really like to see this be broken out as a structure and the bit
shifting games for what really shouldn't be packed into a u_int fixed.
Otherwise this is going to be deadweight that has to persist past
11.0.
Thanks,
-a
On 13 September 2014 01:26, Hans Petter Selasky <hselasky at freebsd.org> wrote:
> Author: hselasky
> Date: Sat Sep 13 08:26:09 2014
> New Revision: 271504
> URL: http://svnweb.freebsd.org/changeset/base/271504
>
> Log:
> Improve transmit sending offload, TSO, algorithm in general.
>
> The current TSO limitation feature only takes the total number of
> bytes in an mbuf chain into account and does not limit by the number
> of mbufs in a chain. Some kinds of hardware is limited by two
> factors. One is the fragment length and the second is the fragment
> count. Both of these limits need to be taken into account when doing
> TSO. Else some kinds of hardware might have to drop completely valid
> mbuf chains because they cannot loaded into the given hardware's DMA
> engine. The new way of doing TSO limitation has been made backwards
> compatible as input from other FreeBSD developers and will use
> defaults for values not set.
>
> MFC after: 1 week
> Sponsored by: Mellanox Technologies
>
> Modified:
> head/sys/dev/oce/oce_if.c
> head/sys/dev/oce/oce_if.h
> head/sys/dev/vmware/vmxnet3/if_vmx.c
> head/sys/dev/vmware/vmxnet3/if_vmxvar.h
> head/sys/dev/xen/netfront/netfront.c
> head/sys/net/if.c
> head/sys/net/if_lagg.c
> head/sys/net/if_var.h
> head/sys/net/if_vlan.c
> head/sys/netinet/tcp_output.c
> head/sys/ofed/drivers/net/mlx4/en_netdev.c
>
> Modified: head/sys/dev/oce/oce_if.c
> ==============================================================================
> --- head/sys/dev/oce/oce_if.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/dev/oce/oce_if.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -1731,7 +1731,10 @@ oce_attach_ifp(POCE_SOFTC sc)
> sc->ifp->if_baudrate = IF_Gbps(10);
>
> #if __FreeBSD_version >= 1000000
> - sc->ifp->if_hw_tsomax = OCE_MAX_TSO_SIZE;
> + sc->ifp->if_hw_tsomax = IF_HW_TSOMAX_BUILD_VALUE(
> + 65535 - (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN) /* bytes */,
> + OCE_MAX_TX_ELEMENTS /* maximum frag count */,
> + 12 /* 4K frag size */);
> #endif
>
> ether_ifattach(sc->ifp, sc->macaddr.mac_addr);
>
> Modified: head/sys/dev/oce/oce_if.h
> ==============================================================================
> --- head/sys/dev/oce/oce_if.h Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/dev/oce/oce_if.h Sat Sep 13 08:26:09 2014 (r271504)
> @@ -152,7 +152,6 @@ extern int mp_ncpus; /* system's total
> #define OCE_MAX_TX_ELEMENTS 29
> #define OCE_MAX_TX_DESC 1024
> #define OCE_MAX_TX_SIZE 65535
> -#define OCE_MAX_TSO_SIZE (65535 - ETHER_HDR_LEN)
> #define OCE_MAX_RX_SIZE 4096
> #define OCE_MAX_RQ_POSTS 255
> #define OCE_DEFAULT_PROMISCUOUS 0
>
> Modified: head/sys/dev/vmware/vmxnet3/if_vmx.c
> ==============================================================================
> --- head/sys/dev/vmware/vmxnet3/if_vmx.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/dev/vmware/vmxnet3/if_vmx.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -1722,7 +1722,11 @@ vmxnet3_setup_interface(struct vmxnet3_s
> ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
> ifp->if_init = vmxnet3_init;
> ifp->if_ioctl = vmxnet3_ioctl;
> - ifp->if_hw_tsomax = VMXNET3_TSO_MAXSIZE;
> +
> + ifp->if_hw_tsomax = IF_HW_TSOMAX_BUILD_VALUE(
> + 65535 - sizeof(struct ether_vlan_header) /* bytes */,
> + VMXNET3_TX_MAXSEGS /* maximum frag count */,
> + VMXNET3_TX_MAXSEGSHIFT /* frag size */);
>
> #ifdef VMXNET3_LEGACY_TX
> ifp->if_start = vmxnet3_start;
>
> Modified: head/sys/dev/vmware/vmxnet3/if_vmxvar.h
> ==============================================================================
> --- head/sys/dev/vmware/vmxnet3/if_vmxvar.h Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/dev/vmware/vmxnet3/if_vmxvar.h Sat Sep 13 08:26:09 2014 (r271504)
> @@ -277,14 +277,13 @@ struct vmxnet3_softc {
> */
> #define VMXNET3_TX_MAXSEGS 32
> #define VMXNET3_TX_MAXSIZE (VMXNET3_TX_MAXSEGS * MCLBYTES)
> -#define VMXNET3_TSO_MAXSIZE \
> - (VMXNET3_TX_MAXSIZE - sizeof(struct ether_vlan_header))
>
> /*
> * Maximum support Tx segments size. The length field in the
> * Tx descriptor is 14 bits.
> */
> -#define VMXNET3_TX_MAXSEGSIZE (1 << 14)
> +#define VMXNET3_TX_MAXSEGSHIFT 14
> +#define VMXNET3_TX_MAXSEGSIZE (1 << VMXNET3_TX_MAXSEGSHIFT)
>
> /*
> * The maximum number of Rx segments we accept. When LRO is enabled,
>
> Modified: head/sys/dev/xen/netfront/netfront.c
> ==============================================================================
> --- head/sys/dev/xen/netfront/netfront.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/dev/xen/netfront/netfront.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -134,7 +134,6 @@ static const int MODPARM_rx_flip = 0;
> * to mirror the Linux MAX_SKB_FRAGS constant.
> */
> #define MAX_TX_REQ_FRAGS (65536 / PAGE_SIZE + 2)
> -#define NF_TSO_MAXBURST ((IP_MAXPACKET / PAGE_SIZE) * MCLBYTES)
>
> #define RX_COPY_THRESHOLD 256
>
> @@ -2102,7 +2101,10 @@ create_netdev(device_t dev)
>
> ifp->if_hwassist = XN_CSUM_FEATURES;
> ifp->if_capabilities = IFCAP_HWCSUM;
> - ifp->if_hw_tsomax = NF_TSO_MAXBURST;
> + ifp->if_hw_tsomax = IF_HW_TSOMAX_BUILD_VALUE(
> + 65535 - (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN) /* bytes */,
> + MAX_TX_REQ_FRAGS /* maximum frag count */,
> + PAGE_SHIFT /* PAGE_SIZE frag size */);
>
> ether_ifattach(ifp, np->mac);
> callout_init(&np->xn_stat_ch, CALLOUT_MPSAFE);
>
> Modified: head/sys/net/if.c
> ==============================================================================
> --- head/sys/net/if.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/net/if.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -423,6 +423,52 @@ if_grow(void)
> }
>
> /*
> + * Compute the least common value of two "if_hw_tsomax" values:
> + */
> +u_int
> +if_hw_tsomax_common(u_int a, u_int b)
> +{
> + u_int a_bytes = IF_HW_TSOMAX_GET_BYTES(a);
> + u_int a_frag_count = IF_HW_TSOMAX_GET_FRAG_COUNT(a);
> + u_int a_frag_size = IF_HW_TSOMAX_GET_FRAG_SIZE(a);
> + u_int b_bytes = IF_HW_TSOMAX_GET_BYTES(b);
> + u_int b_frag_count = IF_HW_TSOMAX_GET_FRAG_COUNT(b);
> + u_int b_frag_size = IF_HW_TSOMAX_GET_FRAG_SIZE(b);
> +
> + return (IF_HW_TSOMAX_BUILD_VALUE(min(a_bytes, b_bytes),
> + min(a_frag_count, b_frag_count),
> + min(a_frag_size, b_frag_size)));
> +}
> +
> +/*
> + * Range check the "if_hw_tsomax" value:
> + */
> +u_int
> +if_hw_tsomax_range_check(u_int a)
> +{
> + u_int a_bytes = IF_HW_TSOMAX_GET_BYTES(a);
> + u_int a_frag_count = IF_HW_TSOMAX_GET_FRAG_COUNT(a);
> + u_int a_frag_size = IF_HW_TSOMAX_GET_FRAG_SIZE(a);
> +
> + /* round down to nearest 4 bytes */
> + a_bytes &= 0xFFFC;
> +
> + /* use default, if zero */
> + if (a_bytes == 0)
> + a_bytes = IF_HW_TSOMAX_DEFAULT_BYTES;
> +
> + /* use default, if zero */
> + if (a_frag_count == 0)
> + a_frag_count = IF_HW_TSOMAX_DEFAULT_FRAG_COUNT;
> +
> + /* use default, if zero */
> + if (a_frag_size == 0)
> + a_frag_size = IF_HW_TSOMAX_DEFAULT_FRAG_SIZE;
> +
> + return (IF_HW_TSOMAX_BUILD_VALUE(a_bytes, a_frag_count, a_frag_size));
> +}
> +
> +/*
> * Allocate a struct ifnet and an index for an interface. A layer 2
> * common structure will also be allocated if an allocation routine is
> * registered for the passed type.
> @@ -445,6 +491,7 @@ if_alloc(u_char type)
> ifp->if_index = idx;
> ifp->if_type = type;
> ifp->if_alloctype = type;
> + ifp->if_hw_tsomax = IF_HW_TSOMAX_DEFAULT_VALUE();
> if (if_com_alloc[type] != NULL) {
> ifp->if_l2com = if_com_alloc[type](type, ifp);
> if (ifp->if_l2com == NULL) {
> @@ -657,16 +704,9 @@ if_attach_internal(struct ifnet *ifp, in
> TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link);
> /* Reliably crash if used uninitialized. */
> ifp->if_broadcastaddr = NULL;
> -
> -#if defined(INET) || defined(INET6)
> - /* Initialize to max value. */
> - if (ifp->if_hw_tsomax == 0)
> - ifp->if_hw_tsomax = min(IP_MAXPACKET, 32 * MCLBYTES -
> - (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN));
> - KASSERT(ifp->if_hw_tsomax <= IP_MAXPACKET &&
> - ifp->if_hw_tsomax >= IP_MAXPACKET / 8,
> - ("%s: tsomax outside of range", __func__));
> -#endif
> + /* range check TSO value */
> + ifp->if_hw_tsomax =
> + if_hw_tsomax_range_check(ifp->if_hw_tsomax);
> }
> #ifdef VIMAGE
> else {
>
> Modified: head/sys/net/if_lagg.c
> ==============================================================================
> --- head/sys/net/if_lagg.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/net/if_lagg.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -445,11 +445,7 @@ lagg_capabilities(struct lagg_softc *sc)
> struct lagg_port *lp;
> int cap = ~0, ena = ~0;
> u_long hwa = ~0UL;
> -#if defined(INET) || defined(INET6)
> - u_int hw_tsomax = IP_MAXPACKET; /* Initialize to the maximum value. */
> -#else
> - u_int hw_tsomax = ~0; /* if_hw_tsomax is only for INET/INET6, but.. */
> -#endif
> + u_int hw_tsomax = IF_HW_TSOMAX_DEFAULT_VALUE();
>
> LAGG_WLOCK_ASSERT(sc);
>
> @@ -458,10 +454,9 @@ lagg_capabilities(struct lagg_softc *sc)
> cap &= lp->lp_ifp->if_capabilities;
> ena &= lp->lp_ifp->if_capenable;
> hwa &= lp->lp_ifp->if_hwassist;
> - /* Set to the minimum value of the lagg ports. */
> - if (lp->lp_ifp->if_hw_tsomax < hw_tsomax &&
> - lp->lp_ifp->if_hw_tsomax > 0)
> - hw_tsomax = lp->lp_ifp->if_hw_tsomax;
> + /* Set to the common value of the lagg ports. */
> + hw_tsomax = if_hw_tsomax_common(hw_tsomax,
> + lp->lp_ifp->if_hw_tsomax);
> }
> cap = (cap == ~0 ? 0 : cap);
> ena = (ena == ~0 ? 0 : ena);
>
> Modified: head/sys/net/if_var.h
> ==============================================================================
> --- head/sys/net/if_var.h Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/net/if_var.h Sat Sep 13 08:26:09 2014 (r271504)
> @@ -120,6 +120,43 @@ typedef int (*if_transmit_fn_t)(if_t, st
> typedef uint64_t (*if_get_counter_t)(if_t, ifnet_counter);
>
> /*
> + * Macros defining how to decode the "if_hw_tsomax" field:
> + */
> +#define IF_HW_TSOMAX_GET_BYTES(x) \
> + ((uint16_t)(x)) /* 32..65535 */
> +
> +#define IF_HW_TSOMAX_GET_FRAG_COUNT(x) \
> + ((uint8_t)((x) >> 16)) /* 1..255 */
> +
> +#define IF_HW_TSOMAX_GET_FRAG_SIZE(x) \
> + ((uint8_t)((x) >> 24)) /* 12..16 */
> +
> +/*
> + * The following macro defines how to build the "if_hw_tsomax"
> + * field. The "bytes" field has unit 1 bytes and declares the maximum
> + * number of bytes which can be transferred by a single transmit
> + * offload, TSO, job. The "bytes" field is rounded down to the neares
> + * 4 bytes to avoid having the hardware do unaligned memory
> + * accesses. The "frag_count" field has unit 1 fragment and declares
> + * the maximum number of fragments a TSO job can contain. The
> + * "frag_size" field has unit logarithm in base 2 of the actual value
> + * in bytes and declares the maximum size of a fragment.
> + */
> +#define IF_HW_TSOMAX_BUILD_VALUE(bytes, frag_count, frag_size) \
> + (((bytes) & 0xFFFC) | (((frag_count) & 0xFF) << 16) | \
> + (((frag_size) & 0xFF) << 24))
> +
> +#define IF_HW_TSOMAX_DEFAULT_BYTES (65536 - 4)
> +#define IF_HW_TSOMAX_DEFAULT_FRAG_COUNT 255
> +#define IF_HW_TSOMAX_DEFAULT_FRAG_SIZE 16
> +
> +#define IF_HW_TSOMAX_DEFAULT_VALUE() \
> + IF_HW_TSOMAX_BUILD_VALUE( \
> + IF_HW_TSOMAX_DEFAULT_BYTES, \
> + IF_HW_TSOMAX_DEFAULT_FRAG_COUNT, \
> + IF_HW_TSOMAX_DEFAULT_FRAG_SIZE)
> +
> +/*
> * Structure defining a network interface.
> *
> * Size ILP32: 592 (approx)
> @@ -222,8 +259,7 @@ struct ifnet {
> if_get_counter_t if_get_counter; /* get counter values */
>
> /* Stuff that's only temporary and doesn't belong here. */
> - u_int if_hw_tsomax; /* tso burst length limit, the minimum
> - * is (IP_MAXPACKET / 8).
> + u_int if_hw_tsomax; /* TSO burst length limits.
> * XXXAO: Have to find a better place
> * for it eventually. */
> /*
> @@ -608,6 +644,10 @@ void if_setioctlfn(if_t ifp, int (*)(if_
> void if_setstartfn(if_t ifp, void (*)(if_t));
> void if_settransmitfn(if_t ifp, if_transmit_fn_t);
> void if_setqflushfn(if_t ifp, if_qflush_fn_t);
> +
> +/* "if_hw_tsomax" related functions */
> +u_int if_hw_tsomax_common(u_int, u_int);
> +u_int if_hw_tsomax_range_check(u_int);
>
> /* Revisit the below. These are inline functions originally */
> int drbr_inuse_drv(if_t ifp, struct buf_ring *br);
>
> Modified: head/sys/net/if_vlan.c
> ==============================================================================
> --- head/sys/net/if_vlan.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/net/if_vlan.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -1511,8 +1511,8 @@ vlan_capabilities(struct ifvlan *ifv)
> * propagate the hardware-assisted flag. TSO on VLANs
> * does not necessarily require hardware VLAN tagging.
> */
> - if (p->if_hw_tsomax > 0)
> - ifp->if_hw_tsomax = p->if_hw_tsomax;
> + ifp->if_hw_tsomax = if_hw_tsomax_common(ifp->if_hw_tsomax,
> + p->if_hw_tsomax);
> if (p->if_capabilities & IFCAP_VLAN_HWTSO)
> ifp->if_capabilities |= p->if_capabilities & IFCAP_TSO;
> if (p->if_capenable & IFCAP_VLAN_HWTSO) {
>
> Modified: head/sys/netinet/tcp_output.c
> ==============================================================================
> --- head/sys/netinet/tcp_output.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/netinet/tcp_output.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$");
> #include <sys/sysctl.h>
>
> #include <net/if.h>
> +#include <net/if_var.h>
> #include <net/route.h>
> #include <net/vnet.h>
>
> @@ -767,18 +768,88 @@ send:
> flags &= ~TH_FIN;
>
> if (tso) {
> + u_int if_hw_tsomax_bytes;
> + u_int if_hw_tsomax_frag_count;
> + u_int if_hw_tsomax_frag_size;
> + struct mbuf *mb;
> + u_int moff;
> + int max_len;
> +
> + /* extract TSO information */
> + if_hw_tsomax_bytes =
> + IF_HW_TSOMAX_GET_BYTES(tp->t_tsomax);
> + if_hw_tsomax_frag_count =
> + IF_HW_TSOMAX_GET_FRAG_COUNT(tp->t_tsomax);
> + if_hw_tsomax_frag_size =
> + IF_HW_TSOMAX_GET_FRAG_SIZE(tp->t_tsomax);
> +
> + /* compute maximum TSO length */
> + max_len = (if_hw_tsomax_bytes - hdrlen);
> +
> + /* clamp maximum length value */
> + if (max_len > IP_MAXPACKET)
> + max_len = IP_MAXPACKET;
> + else if (max_len < 0)
> + max_len = 0;
> +
> + /* get smallest length */
> + if (len > (u_int)max_len) {
> + if (max_len != 0)
> + sendalot = 1;
> + len = (u_int)max_len;
> + }
> +
> KASSERT(ipoptlen == 0,
> ("%s: TSO can't do IP options", __func__));
>
> + max_len = 0;
> + mb = sbsndptr(&so->so_snd, off, len, &moff);
> +
> + /* now make sure the number of fragments fit too */
> + while (mb != NULL && (u_int)max_len < len) {
> + u_int cur_length;
> + u_int cur_frags;
> +
> + /*
> + * Get length of mbuf fragment and how
> + * many hardware frags, rounded up, it
> + * would use:
> + */
> + cur_length = (mb->m_len - moff);
> + cur_frags = (cur_length +
> + (1 << if_hw_tsomax_frag_size) - 1) >>
> + if_hw_tsomax_frag_size;
> +
> + /* Handle special case: Zero Length Mbuf */
> + if (cur_frags == 0)
> + cur_frags = 1;
> +
> + /*
> + * Check if the fragment limit will be
> + * reached or exceeded:
> + */
> + if (cur_frags >= if_hw_tsomax_frag_count) {
> + max_len += min(cur_length,
> + if_hw_tsomax_frag_count <<
> + if_hw_tsomax_frag_size);
> + break;
> + }
> + max_len += cur_length;
> + if_hw_tsomax_frag_count -= cur_frags;
> + moff = 0;
> + mb = mb->m_next;
> + }
> +
> /*
> * Limit a burst to t_tsomax minus IP,
> * TCP and options length to keep ip->ip_len
> * from overflowing or exceeding the maximum
> * length allowed by the network interface.
> */
> - if (len > tp->t_tsomax - hdrlen) {
> - len = tp->t_tsomax - hdrlen;
> - sendalot = 1;
> + if (len > (u_int)max_len) {
> + if (max_len != 0)
> + sendalot = 1;
> + len = (u_int)max_len;
> }
>
> /*
>
> Modified: head/sys/ofed/drivers/net/mlx4/en_netdev.c
> ==============================================================================
> --- head/sys/ofed/drivers/net/mlx4/en_netdev.c Sat Sep 13 07:45:03 2014 (r271503)
> +++ head/sys/ofed/drivers/net/mlx4/en_netdev.c Sat Sep 13 08:26:09 2014 (r271504)
> @@ -673,6 +673,12 @@ int mlx4_en_do_start_port(struct net_dev
> else
> priv->rx_csum = 0;
>
> + /* set TSO limits so that we don't have to drop TX packets */
> + dev->if_hw_tsomax = IF_HW_TSOMAX_BUILD_VALUE(
> + 65535 - sizeof(struct ether_vlan_header) /* bytes */,
> + 16 /* maximum frag count */,
> + 16 /* can do up to 4GByte */);
> +
> err = mlx4_wol_read(priv->mdev->dev, &config, priv->port);
> if (err) {
> en_err(priv, "Failed to get WoL info, unable to modify\n");
>
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