freebsd-skq/sys/dev/cxgbe/t4_mp_ring.h
np 23f1bda6c8 cxgbe(4): changes in the Tx path to help increase tx coalescing.
- Ask the firmware for the number of frames that can be stuffed in one
  work request.

- Modify mp_ring to increase the likelihood of tx coalescing when there
  are just one or two threads that are doing most of the tx.  Add teeth
  to the abdication mechanism by pushing the consumer lock into mp_ring.
  This reduces the likelihood that a consumer will get stuck with all
  the work even though it is above its budget.

- Add support for coalesced tx WR to the VF driver.  This, with the
  changes above, results in a 7x improvement in the tx pps of the VF
  driver for some common cases.  The firmware vets the L2 headers
  submitted by the VF driver and it's a big win if the checks are
  performed for a batch of packets and not each one individually.

Reviewed by:	jhb@
MFC after:	2 weeks
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D25454
2020-07-03 04:44:23 +00:00

74 lines
2.6 KiB
C

/*-
* Copyright (c) 2014 Chelsio Communications, Inc.
* All rights reserved.
* Written by: Navdeep Parhar <np@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*
*/
#ifndef __CXGBE_MP_RING_H
#define __CXGBE_MP_RING_H
#ifndef _KERNEL
#error "no user-serviceable parts inside"
#endif
struct mp_ring;
typedef u_int (*ring_drain_t)(struct mp_ring *, u_int, u_int, bool *);
typedef u_int (*ring_can_drain_t)(struct mp_ring *);
struct mp_ring {
volatile uint64_t state __aligned(CACHE_LINE_SIZE);
struct malloc_type * mt;
int size __aligned(CACHE_LINE_SIZE);
void * cookie;
ring_drain_t drain;
ring_can_drain_t can_drain; /* cheap, may be unreliable */
struct mtx * cons_lock;
counter_u64_t dropped;
counter_u64_t consumer[4];
counter_u64_t not_consumer;
counter_u64_t abdications;
counter_u64_t consumed;
counter_u64_t cons_idle;
counter_u64_t cons_idle2;
counter_u64_t stalls;
void * volatile items[] __aligned(CACHE_LINE_SIZE);
};
int mp_ring_alloc(struct mp_ring **, int, void *, ring_drain_t,
ring_can_drain_t, struct malloc_type *, struct mtx *, int);
void mp_ring_free(struct mp_ring *);
int mp_ring_enqueue(struct mp_ring *, void **, int, int);
void mp_ring_check_drainage(struct mp_ring *, int);
void mp_ring_reset_stats(struct mp_ring *);
bool mp_ring_is_idle(struct mp_ring *);
void mp_ring_sysctls(struct mp_ring *, struct sysctl_ctx_list *,
struct sysctl_oid_list *);
#endif