freebsd-skq/sys/net/iflib_private.h
Stephen Hurd 5ee36c68e1 Work around lack of TX IRQs in iflib for netmap
When poll() is called via netmap, txsync is initially called,
and if there are no available buffers to reclaim, it waits for the driver
to notify of new buffers. Since the TX IRQ is generally not used in iflib
drivers, this ends up causing a timeout.

Work around this by having the reclaim DELAY(1) if it's initially unable
to reclaim anything, then schedule the tx task, which will spin by
continuously rescheduling itself until some buffers are reclaimed. In
general, the delay is enough to allow some buffers to be reclaimed, so
spinning is minimized.

Reported by:	Johannes Lundberg <johalun0@gmail.com>
Reviewed by:	sbruno
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D15455
2018-05-16 21:03:22 +00:00

76 lines
2.4 KiB
C

/*-
* Copyright (c) 2018, Matthew Macy (mmacy@freebsd.org)
* All rights reserved.
*
* 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. Neither the name of Matthew Macy nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 __NET_IFLIB_PRIVATE_H_
#define __NET_IFLIB_PRIVATE_H_
#define IFC_LEGACY 0x001
#define IFC_QFLUSH 0x002
#define IFC_MULTISEG 0x004
#define IFC_DMAR 0x008
#define IFC_SC_ALLOCATED 0x010
#define IFC_INIT_DONE 0x020
#define IFC_PREFETCH 0x040
#define IFC_DO_RESET 0x080
#define IFC_DO_WATCHDOG 0x100
#define IFC_CHECK_HUNG 0x200
#define IFC_PSEUDO 0x400
#define IFC_NETMAP_TX_IRQ 0x80000000
MALLOC_DECLARE(M_IFLIB);
#define IFLIB_MAX_TX_BYTES (2*1024*1024)
#define IFLIB_MIN_TX_BYTES (8*1024)
#define IFLIB_DEFAULT_TX_QDEPTH 2048
struct iflib_cloneattach_ctx {
struct if_clone *cc_ifc;
caddr_t cc_params;
const char *cc_name;
int cc_len;
};
extern driver_t iflib_pseudodriver;
int noop_attach(device_t dev);
int iflib_pseudo_detach(device_t dev);
int iflib_pseudo_register(device_t dev, if_shared_ctx_t sctx, if_ctx_t *ctxp,
struct iflib_cloneattach_ctx *clctx);
int iflib_pseudo_deregister(if_ctx_t ctx);
uint32_t iflib_get_flags(if_ctx_t ctx);
void iflib_set_detach(if_ctx_t ctx);
void iflib_stop(if_ctx_t ctx);
#endif