[ovs-dev] [PATCH 3/4] dp-packet: Remove ofpbuf dependency.

Kavanagh, Mark B mark.b.kavanagh at intel.com
Tue Mar 3 17:01:04 UTC 2015


> Currently dp-packet make use of ofpbuf for managing packet
> buffers. That complicates ofpbuf, by making dp-packet
> independent of ofpbuf both libraries can be optimized for
> their own use case.
> This avoids mapping operation between ofpbuf and dp_packet
> in datapath upcalls.
> 
> Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
> ---
>  lib/bfd.c                      |   23 +-
>  lib/bfd.h                      |    6 +-
>  lib/cfm.c                      |   12 +-
>  lib/cfm.h                      |    6 +-
>  lib/dp-packet.c                |  556 +++++++++++++++++++++++++++++++++++++--
>  lib/dp-packet.h                |  442 ++++++++++++++++++++++++++++++--
>  lib/dpif-netdev.c              |   44 ++--
>  lib/dpif-netdev.h              |    8 +-
>  lib/dpif-netlink.c             |   20 +-
>  lib/dpif.c                     |   31 +--
>  lib/dpif.h                     |   11 +-
>  lib/flow.c                     |   79 +++---
>  lib/flow.h                     |   32 +--
>  lib/lacp.c                     |    8 +-
>  lib/lacp.h                     |    2 +-
>  lib/learning-switch.c          |   11 +-
>  lib/netdev-bsd.c               |   31 +--
>  lib/netdev-dpdk.c              |   11 +-
>  lib/netdev-dummy.c             |   94 ++++----
>  lib/netdev-linux.c             |   35 ++--
>  lib/netdev-vport.c             |   47 ++--
>  lib/netdev.c                   |    4 +-
>  lib/odp-execute.c              |  105 ++++----
>  lib/ofp-print.c                |   22 +-
>  lib/packets.c                  |  158 ++++++------
>  lib/packets.h                  |   34 ++--
>  lib/pcap-file.c                |   48 ++--
>  lib/pcap-file.h                |   10 +-
>  lib/rstp-common.h              |    2 +-
>  lib/rstp-state-machines.c      |   15 +-
>  lib/rstp.c                     |    3 +-
>  lib/rstp.h                     |    4 +-
>  lib/stp.c                      |   19 +-
>  lib/stp.h                      |    4 +-
>  ofproto/bond.c                 |    7 +-
>  ofproto/bond.h                 |    2 +-
>  ofproto/connmgr.c              |    2 +-
>  ofproto/connmgr.h              |    2 +-
>  ofproto/fail-open.c            |   15 +-
>  ofproto/ofproto-dpif-ipfix.c   |  101 ++++----
>  ofproto/ofproto-dpif-ipfix.h   |    6 +-
>  ofproto/ofproto-dpif-monitor.c |   19 +-
>  ofproto/ofproto-dpif-sflow.c   |    8 +-
>  ofproto/ofproto-dpif-sflow.h   |    2 +-
>  ofproto/ofproto-dpif-upcall.c  |   35 ++--
>  ofproto/ofproto-dpif-xlate.c   |   54 ++--
>  ofproto/ofproto-dpif-xlate.h   |    7 +-
>  ofproto/ofproto-dpif.c         |   91 ++++----
>  ofproto/ofproto-dpif.h         |    6 +-
>  ofproto/ofproto-provider.h     |    4 +-
>  ofproto/ofproto.c              |   19 +-
>  ofproto/pktbuf.c               |   16 +-
>  ofproto/pktbuf.h               |    4 +-
>  tests/test-flows.c             |   11 +-
>  tests/test-rstp.c              |    9 +-
>  tests/test-stp.c               |    9 +-
>  utilities/ovs-ofctl.c          |   42 ++--
>  57 files changed, 1639 insertions(+), 769 deletions(-)

General: what impacts (if any) to performance do these changes have? Are any figures available (e.g. for Phy-Phy use case)?
> 
> diff --git a/lib/bfd.c b/lib/bfd.c
> index 3db1d57..62ace8f 100644
> --- a/lib/bfd.c
> +++ b/lib/bfd.c
> @@ -35,6 +35,7 @@

(snip)

> @@ -741,7 +742,7 @@ bfd_process_packet(struct bfd *bfd, const struct flow *flow,
>       * If the Length field is greater than the payload of the encapsulating
>       * protocol, the packet MUST be discarded.
>       *
> -     * Note that we make this check implicity.  Above we use ofpbuf_at() to
> +     * Note that we make this check implicity.  Above we use dp_packet_at() to

Typo in comment: 'implicity' (sic)

(snip)

> diff --git a/lib/dp-packet.c b/lib/dp-packet.c
> index d77f8e4..b90f678 100644
> --- a/lib/dp-packet.c
> +++ b/lib/dp-packet.c
> @@ -1,5 +1,5 @@
>  /*
> - * Copyright (c) 2014 Nicira, Inc.
> + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
>   *
>   * Licensed under the Apache License, Version 2.0 (the "License");
>   * you may not use this file except in compliance with the License.
> @@ -15,57 +15,555 @@
>   */
> 
>  #include <config.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include "dynamic-string.h"
> +#include "netdev-dpdk.h"
>  #include "dp-packet.h"
> +#include "util.h"
> 

(snip)

> +/* Frees memory that 'b' points to. */
> +void
> +dp_packet_uninit(struct dp_packet *b)
> +{
> +    if (b) {
> +        if (b->source == DPBUF_MALLOC) {
> +            free(dp_packet_base(b));
> +        } else if (b->source == DPBUF_DPDK) {
> +#ifdef DPDK_NETDEV
> +            /* If this dp_packet was allocated by DPDK it must have been
> +             * created as a dp_packet */
> +            free_dpdk_buf((struct dp_packet*) b);
> +#else
> +            ovs_assert(b->source != DPBUF_DPDK);

The else condition ensures that b->source is DPBUF_DPDK - how can this assert ever be true? 

> +#endif
> +        }
> +    }
> +}
> +
>
> +/* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
> + * bytes of headroom and tailroom, respectively. */
> +static void
> +dp_packet_resize__(struct dp_packet *b, size_t new_headroom, size_t new_tailroom)
> +{
> +    void *new_base, *new_data;
> +    size_t new_allocated;
> +
> +    new_allocated = new_headroom + dp_packet_size(b) + new_tailroom;
> +
> +    switch (b->source) {
> +    case DPBUF_DPDK:
> +        OVS_NOT_REACHED();
> +
> +    case DPBUF_MALLOC:
> +        if (new_headroom == dp_packet_headroom(b)) {
> +            new_base = xrealloc(dp_packet_base(b), new_allocated);
> +        } else {
> +            new_base = xmalloc(new_allocated);
> +            dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
> +            free(dp_packet_base(b));
> +        }
> +        break;
> 
> -        p->ofpbuf.frame = (char *) b->frame + data_delta;
> +    case DPBUF_STACK:
> +        OVS_NOT_REACHED();
> +
> +    case DPBUF_STUB:
> +        b->source = DPBUF_MALLOC;
> +        new_base = xmalloc(new_allocated);
> +        dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
> +        break;
> +
> +    default:
> +        OVS_NOT_REACHED();
>      }
> -    p->ofpbuf.l2_5_ofs = b->l2_5_ofs;
> -    p->ofpbuf.l3_ofs = b->l3_ofs;
> -    p->ofpbuf.l4_ofs = b->l4_ofs;
> 
> +    b->allocated = new_allocated;
> +    dp_packet_set_base(b, new_base);
> +
> +    new_data = (char *) new_base + new_headroom;
> +    if (dp_packet_data(b) != new_data) {
> +        if (b->frame) {
> +            uintptr_t data_delta = (char *) new_data - (char *) dp_packet_data(b);
> +

General: You already know this, but just to state it explicitly: these changes won't work with DPDK versions > 1.7.1

> +            b->frame = (char *) b->frame + data_delta;
> +        }
> +        dp_packet_set_data(b, new_data);

(snip)

> +/* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
> + * For example, a 'delta' of 1 would cause each byte of data to move one byte
> + * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
> + * byte to move one byte backward (from 'p' to 'p-1'). */
> +void
> +dp_packet_shift(struct dp_packet *b, int delta)
> +{
> +    ovs_assert(delta > 0 ? delta <= dp_packet_tailroom(b)
> +               : delta < 0 ? -delta <= dp_packet_headroom(b)
> +               : true);
> +
> +    if (delta != 0) {
> +        char *dst = (char *) dp_packet_data(b) + delta;
> +        memmove(dst, dp_packet_data(b), dp_packet_size(b));

Presumably, it is the caller's responsibility to ensure that the memory at 'dst' is not in use?

> +        dp_packet_set_data(b, dst);
> +    }
> +}
> +

(snip)

> +
> +static inline void
> +dp_packet_adjust_layer_offset(uint16_t *offset, int increment)
>  {
> -    struct dp_packet *newp;
> +    if (*offset != UINT16_MAX) {
> +        *offset += increment;

Is a warning needed if offset wraps around?

(snip)

> diff --git a/lib/dp-packet.h b/lib/dp-packet.h
> index 74abdec..e23660d 100644
> --- a/lib/dp-packet.h
> +++ b/lib/dp-packet.h
> @@ -1,5 +1,5 @@
>  /*
> - * Copyright (c) 2014 Nicira, Inc.
> + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
>   *
>   * Licensed under the Apache License, Version 2.0 (the "License");
>   * you may not use this file except in compliance with the License.
> @@ -14,43 +14,451 @@
>   * limitations under the License.
>   */
> 
> -#ifndef PACKET_DPIF_H
> -#define PACKET_DPIF_H 1
> +#ifndef DPBUF_H
> +#define DPBUF_H 1
> 
> -#include "ofpbuf.h"
> +#include <stddef.h>
> +#include <stdint.h>
> +#include "list.h"
> +#include "packets.h"
> +#include "util.h"
> +#include "netdev-dpdk.h"

General: Rearrange includes alphabetically, if possible

> 
>  #ifdef  __cplusplus
>  extern "C" {
>  #endif
> 
> -/* A packet received from a netdev and passed to a dpif. */
> +enum OVS_PACKED_ENUM dp_packet_source {
> +    DPBUF_MALLOC,              /* Obtained via malloc(). */
> +    DPBUF_STACK,               /* Un-movable stack space or static buffer. */
> +    DPBUF_STUB,                /* Starts on stack, may expand into heap. */
> +    DPBUF_DPDK,                /* buffer data is from DPDK allocated memory.
> +                                   ref to build_dp_packet() in netdev-dpdk. */

Alignment is off on second line of comment above


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