fc271df341
"qsort()". The kernel's "qsort()" routine can in worst case spend O(N*N) amount of comparisons before the input array is sorted. It can also recurse a significant amount of times using up the kernel's interrupt thread stack. The custom sorting routine takes advantage of that the sorting key is only 64 bits. Based on set and cleared bits in the sorting key it partitions the array until it is sorted. This process has a recursion limit of 64 times, due to the number of set and cleared bits which can occur. Compiled with -O2 the sorting routine was measured to use 64-bytes of stack. Multiplying this by 64 gives a maximum stack consumption of 4096 bytes for AMD64. The same applies to the execution time, that the array to be sorted will not be traversed more than 64 times. When serving roughly 80Gb/s with 80K TCP connections, the old method consisting of "qsort()" and "tcp_lro_mbuf_compare_header()" used 1.4% CPU, while the new "tcp_lro_sort()" used 1.1% for LRO related sorting as measured by Intel Vtune. The testing was done using a sysctl to toggle between "qsort()" and "tcp_lro_sort()". Differential Revision: https://reviews.freebsd.org/D6472 Sponsored by: Mellanox Technologies Tested by: Netflix Reviewed by: gallatin, rrs, sephe, transport
119 lines
3.6 KiB
C
119 lines
3.6 KiB
C
/*-
|
|
* Copyright (c) 2006, Myricom Inc.
|
|
* Copyright (c) 2008, Intel Corporation.
|
|
* Copyright (c) 2016 Mellanox Technologies.
|
|
* 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. 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 _TCP_LRO_H_
|
|
#define _TCP_LRO_H_
|
|
|
|
#include <sys/time.h>
|
|
|
|
#ifndef TCP_LRO_ENTRIES
|
|
/* Define default number of LRO entries per RX queue */
|
|
#define TCP_LRO_ENTRIES 8
|
|
#endif
|
|
|
|
struct lro_entry {
|
|
LIST_ENTRY(lro_entry) next;
|
|
struct mbuf *m_head;
|
|
struct mbuf *m_tail;
|
|
union {
|
|
struct ip *ip4;
|
|
struct ip6_hdr *ip6;
|
|
} leip;
|
|
union {
|
|
in_addr_t s_ip4;
|
|
struct in6_addr s_ip6;
|
|
} lesource;
|
|
union {
|
|
in_addr_t d_ip4;
|
|
struct in6_addr d_ip6;
|
|
} ledest;
|
|
uint16_t source_port;
|
|
uint16_t dest_port;
|
|
uint16_t eh_type; /* EthernetHeader type. */
|
|
uint16_t append_cnt;
|
|
uint32_t p_len; /* IP header payload length. */
|
|
uint32_t ulp_csum; /* TCP, etc. checksum. */
|
|
uint32_t next_seq; /* tcp_seq */
|
|
uint32_t ack_seq; /* tcp_seq */
|
|
uint32_t tsval;
|
|
uint32_t tsecr;
|
|
uint16_t window;
|
|
uint16_t timestamp; /* flag, not a TCP hdr field. */
|
|
struct timeval mtime;
|
|
};
|
|
LIST_HEAD(lro_head, lro_entry);
|
|
|
|
#define le_ip4 leip.ip4
|
|
#define le_ip6 leip.ip6
|
|
#define source_ip4 lesource.s_ip4
|
|
#define dest_ip4 ledest.d_ip4
|
|
#define source_ip6 lesource.s_ip6
|
|
#define dest_ip6 ledest.d_ip6
|
|
|
|
struct lro_mbuf_sort {
|
|
uint64_t seq;
|
|
struct mbuf *mb;
|
|
};
|
|
|
|
/* NB: This is part of driver structs. */
|
|
struct lro_ctrl {
|
|
struct ifnet *ifp;
|
|
struct lro_mbuf_sort *lro_mbuf_data;
|
|
uint64_t lro_queued;
|
|
uint64_t lro_flushed;
|
|
uint64_t lro_bad_csum;
|
|
unsigned lro_cnt;
|
|
unsigned lro_mbuf_count;
|
|
unsigned lro_mbuf_max;
|
|
unsigned short lro_ackcnt_lim; /* max # of aggregated ACKs */
|
|
unsigned lro_length_lim; /* max len of aggregated data */
|
|
|
|
struct lro_head lro_active;
|
|
struct lro_head lro_free;
|
|
};
|
|
|
|
#define TCP_LRO_LENGTH_MAX 65535
|
|
#define TCP_LRO_ACKCNT_MAX 65535 /* unlimited */
|
|
|
|
int tcp_lro_init(struct lro_ctrl *);
|
|
int tcp_lro_init_args(struct lro_ctrl *, struct ifnet *, unsigned, unsigned);
|
|
void tcp_lro_free(struct lro_ctrl *);
|
|
void tcp_lro_flush_inactive(struct lro_ctrl *, const struct timeval *);
|
|
void tcp_lro_flush(struct lro_ctrl *, struct lro_entry *);
|
|
void tcp_lro_flush_all(struct lro_ctrl *);
|
|
int tcp_lro_rx(struct lro_ctrl *, struct mbuf *, uint32_t);
|
|
void tcp_lro_queue_mbuf(struct lro_ctrl *, struct mbuf *);
|
|
|
|
#define TCP_LRO_NO_ENTRIES -2
|
|
#define TCP_LRO_CANNOT -1
|
|
#define TCP_LRO_NOT_SUPPORTED 1
|
|
|
|
#endif /* _TCP_LRO_H_ */
|