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freebsd-dev/sys/netinet/tcp_hpts.c
Randall Stewart 3ee9c3c4eb This commit brings in the TCP high precision timer system (tcp_hpts). 
It is the forerunner/foundational work of bringing in both Rack and BBR
which use hpts for pacing out packets. The feature is optional and requires
the TCPHPTS option to be enabled before the feature will be active. TCP
modules that use it must assure that the base component is compile in
the kernel in which they are loaded.

MFC after:	Never
Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D15020
2018-04-19 13:37:59 +00:00

1965 lines
54 KiB
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/*-
* Copyright (c) 2016-8
* Netflix Inc. 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 REGENTS 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 REGENTS 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_tcpdebug.h"
/**
* Some notes about usage.
*
* The tcp_hpts system is designed to provide a high precision timer
* system for tcp. Its main purpose is to provide a mechanism for
* pacing packets out onto the wire. It can be used in two ways
* by a given TCP stack (and those two methods can be used simultaneously).
*
* First, and probably the main thing its used by Rack and BBR for, it can
* be used to call tcp_output() of a transport stack at some time in the future.
* The normal way this is done is that tcp_output() of the stack schedules
* itself to be called again by calling tcp_hpts_insert(tcpcb, slot). The
* slot is the time from now that the stack wants to be called but it
* must be converted to tcp_hpts's notion of slot. This is done with
* one of the macros HPTS_MS_TO_SLOTS or HPTS_USEC_TO_SLOTS. So a typical
* call from the tcp_output() routine might look like:
*
* tcp_hpts_insert(tp, HPTS_USEC_TO_SLOTS(550));
*
* The above would schedule tcp_ouput() to be called in 550 useconds.
* Note that if using this mechanism the stack will want to add near
* its top a check to prevent unwanted calls (from user land or the
* arrival of incoming ack's). So it would add something like:
*
* if (inp->inp_in_hpts)
* return;
*
* to prevent output processing until the time alotted has gone by.
* Of course this is a bare bones example and the stack will probably
* have more consideration then just the above.
*
* Now the tcp_hpts system will call tcp_output in one of two forms,
* it will first check to see if the stack as defined a
* tfb_tcp_output_wtime() function, if so that is the routine it
* will call, if that function is not defined then it will call the
* tfb_tcp_output() function. The only difference between these
* two calls is that the former passes the time in to the function
* so the function does not have to access the time (which tcp_hpts
* already has). What these functions do is of course totally up
* to the individual tcp stack.
*
* Now the second function (actually two functions I guess :D)
* the tcp_hpts system provides is the ability to either abort
* a connection (later) or process input on a connection.
* Why would you want to do this? To keep processor locality.
*
* So in order to use the input redirection function the
* stack changes its tcp_do_segment() routine to instead
* of process the data call the function:
*
* tcp_queue_pkt_to_input()
*
* You will note that the arguments to this function look
* a lot like tcp_do_segments's arguments. This function
* will assure that the tcp_hpts system will
* call the functions tfb_tcp_hpts_do_segment() from the
* correct CPU. Note that multiple calls can get pushed
* into the tcp_hpts system this will be indicated by
* the next to last argument to tfb_tcp_hpts_do_segment()
* (nxt_pkt). If nxt_pkt is a 1 then another packet is
* coming. If nxt_pkt is a 0 then this is the last call
* that the tcp_hpts system has available for the tcp stack.
*
* The other point of the input system is to be able to safely
* drop a tcp connection without worrying about the recursive
* locking that may be occuring on the INP_WLOCK. So if
* a stack wants to drop a connection it calls:
*
* tcp_set_inp_to_drop(tp, ETIMEDOUT)
*
* To schedule the tcp_hpts system to call
*
* tcp_drop(tp, drop_reason)
*
* at a future point. This is quite handy to prevent locking
* issues when dropping connections.
*
*/
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/hhook.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h> /* for proc0 declaration */
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/refcount.h>
#include <sys/sched.h>
#include <sys/queue.h>
#include <sys/smp.h>
#include <sys/counter.h>
#include <sys/time.h>
#include <sys/kthread.h>
#include <sys/kern_prefetch.h>
#include <vm/uma.h>
#include <net/route.h>
#include <net/vnet.h>
#define TCPSTATES /* for logging */
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_pcb.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h> /* required for icmp_var.h */
#include <netinet/icmp_var.h> /* for ICMP_BANDLIM */
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#define TCPOUTFLAGS
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
#include <netinet/cc/cc.h>
#include <netinet/tcp_hpts.h>
#ifdef tcpdebug
#include <netinet/tcp_debug.h>
#endif /* tcpdebug */
#ifdef tcp_offload
#include <netinet/tcp_offload.h>
#endif
#ifdef ipsec
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#endif /* ipsec */
#include "opt_rss.h"
MALLOC_DEFINE(M_TCPHPTS, "tcp_hpts", "TCP hpts");
#ifdef RSS
static int tcp_bind_threads = 1;
#else
static int tcp_bind_threads = 0;
#endif
TUNABLE_INT("net.inet.tcp.bind_hptss", &tcp_bind_threads);
static uint32_t tcp_hpts_logging_size = DEFAULT_HPTS_LOG;
TUNABLE_INT("net.inet.tcp.hpts_logging_sz", &tcp_hpts_logging_size);
static struct tcp_hptsi tcp_pace;
static int
tcp_hptsi_lock_inpinfo(struct inpcb *inp,
struct tcpcb **tp);
static void tcp_wakehpts(struct tcp_hpts_entry *p);
static void tcp_wakeinput(struct tcp_hpts_entry *p);
static void tcp_input_data(struct tcp_hpts_entry *hpts, struct timeval *tv);
static void tcp_hptsi(struct tcp_hpts_entry *hpts, struct timeval *ctick);
static void tcp_hpts_thread(void *ctx);
static void tcp_init_hptsi(void *st);
int32_t tcp_min_hptsi_time = DEFAULT_MIN_SLEEP;
static int32_t tcp_hpts_callout_skip_swi = 0;
SYSCTL_DECL(_net_inet_tcp);
SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hpts, CTLFLAG_RW, 0, "TCP Hpts controls");
#define timersub(tvp, uvp, vvp) \
do { \
(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \
(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \
if ((vvp)->tv_usec < 0) { \
(vvp)->tv_sec--; \
(vvp)->tv_usec += 1000000; \
} \
} while (0)
static int32_t logging_on = 0;
static int32_t hpts_sleep_max = (NUM_OF_HPTSI_SLOTS - 2);
static int32_t tcp_hpts_precision = 120;
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, precision, CTLFLAG_RW,
&tcp_hpts_precision, 120,
"Value for PRE() precision of callout");
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, logging, CTLFLAG_RW,
&logging_on, 0,
"Turn on logging if compiled in");
counter_u64_t hpts_loops;
SYSCTL_COUNTER_U64(_net_inet_tcp_hpts, OID_AUTO, loops, CTLFLAG_RD,
&hpts_loops, "Number of times hpts had to loop to catch up");
counter_u64_t back_tosleep;
SYSCTL_COUNTER_U64(_net_inet_tcp_hpts, OID_AUTO, no_tcbsfound, CTLFLAG_RD,
&back_tosleep, "Number of times hpts found no tcbs");
static int32_t in_newts_every_tcb = 0;
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, in_tsperpcb, CTLFLAG_RW,
&in_newts_every_tcb, 0,
"Do we have a new cts every tcb we process for input");
static int32_t in_ts_percision = 0;
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, in_tspercision, CTLFLAG_RW,
&in_ts_percision, 0,
"Do we use percise timestamp for clients on input");
static int32_t out_newts_every_tcb = 0;
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, out_tsperpcb, CTLFLAG_RW,
&out_newts_every_tcb, 0,
"Do we have a new cts every tcb we process for output");
static int32_t out_ts_percision = 0;
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, out_tspercision, CTLFLAG_RW,
&out_ts_percision, 0,
"Do we use a percise timestamp for every output cts");
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, maxsleep, CTLFLAG_RW,
&hpts_sleep_max, 0,
"The maximum time the hpts will sleep <1 - 254>");
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, minsleep, CTLFLAG_RW,
&tcp_min_hptsi_time, 0,
"The minimum time the hpts must sleep before processing more slots");
SYSCTL_INT(_net_inet_tcp_hpts, OID_AUTO, skip_swi, CTLFLAG_RW,
&tcp_hpts_callout_skip_swi, 0,
"Do we have the callout call directly to the hpts?");
static void
__tcp_hpts_log_it(struct tcp_hpts_entry *hpts, struct inpcb *inp, int event, uint32_t slot,
uint32_t ticknow, int32_t line)
{
struct hpts_log *pl;
HPTS_MTX_ASSERT(hpts);
if (hpts->p_log == NULL)
return;
pl = &hpts->p_log[hpts->p_log_at];
hpts->p_log_at++;
if (hpts->p_log_at >= hpts->p_logsize) {
hpts->p_log_at = 0;
hpts->p_log_wrapped = 1;
}
pl->inp = inp;
if (inp) {
pl->t_paceslot = inp->inp_hptsslot;
pl->t_hptsreq = inp->inp_hpts_request;
pl->p_onhpts = inp->inp_in_hpts;
pl->p_oninput = inp->inp_in_input;
} else {
pl->t_paceslot = 0;
pl->t_hptsreq = 0;
pl->p_onhpts = 0;
pl->p_oninput = 0;
}
pl->is_notempty = 1;
pl->event = event;
pl->line = line;
pl->cts = tcp_get_usecs(NULL);
pl->p_curtick = hpts->p_curtick;
pl->p_prevtick = hpts->p_prevtick;
pl->p_on_queue_cnt = hpts->p_on_queue_cnt;
pl->ticknow = ticknow;
pl->slot_req = slot;
pl->p_nxt_slot = hpts->p_nxt_slot;
pl->p_cur_slot = hpts->p_cur_slot;
pl->p_hpts_sleep_time = hpts->p_hpts_sleep_time;
pl->p_flags = (hpts->p_cpu & 0x7f);
pl->p_flags <<= 7;
pl->p_flags |= (hpts->p_num & 0x7f);
pl->p_flags <<= 2;
if (hpts->p_hpts_active) {
pl->p_flags |= HPTS_HPTS_ACTIVE;
}
}
#define tcp_hpts_log_it(a, b, c, d, e) __tcp_hpts_log_it(a, b, c, d, e, __LINE__)
static void
hpts_timeout_swi(void *arg)
{
struct tcp_hpts_entry *hpts;
hpts = (struct tcp_hpts_entry *)arg;
swi_sched(hpts->ie_cookie, 0);
}
static void
hpts_timeout_dir(void *arg)
{
tcp_hpts_thread(arg);
}
static inline void
hpts_sane_pace_remove(struct tcp_hpts_entry *hpts, struct inpcb *inp, struct hptsh *head, int clear)
{
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx) == 0) {
/* We don't own the mutex? */
panic("%s: hpts:%p inp:%p no hpts mutex", __FUNCTION__, hpts, inp);
}
if (hpts->p_cpu != inp->inp_hpts_cpu) {
/* It is not the right cpu/mutex? */
panic("%s: hpts:%p inp:%p incorrect CPU", __FUNCTION__, hpts, inp);
}
if (inp->inp_in_hpts == 0) {
/* We are not on the hpts? */
panic("%s: hpts:%p inp:%p not on the hpts?", __FUNCTION__, hpts, inp);
}
if (TAILQ_EMPTY(head) &&
(hpts->p_on_queue_cnt != 0)) {
/* We should not be empty with a queue count */
panic("%s hpts:%p hpts bucket empty but cnt:%d",
__FUNCTION__, hpts, hpts->p_on_queue_cnt);
}
#endif
TAILQ_REMOVE(head, inp, inp_hpts);
hpts->p_on_queue_cnt--;
if (hpts->p_on_queue_cnt < 0) {
/* Count should not go negative .. */
#ifdef INVARIANTS
panic("Hpts goes negative inp:%p hpts:%p",
inp, hpts);
#endif
hpts->p_on_queue_cnt = 0;
}
if (clear) {
inp->inp_hpts_request = 0;
inp->inp_in_hpts = 0;
}
}
static inline void
hpts_sane_pace_insert(struct tcp_hpts_entry *hpts, struct inpcb *inp, struct hptsh *head, int line, int noref)
{
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx) == 0) {
/* We don't own the mutex? */
panic("%s: hpts:%p inp:%p no hpts mutex", __FUNCTION__, hpts, inp);
}
if (hpts->p_cpu != inp->inp_hpts_cpu) {
/* It is not the right cpu/mutex? */
panic("%s: hpts:%p inp:%p incorrect CPU", __FUNCTION__, hpts, inp);
}
if ((noref == 0) && (inp->inp_in_hpts == 1)) {
/* We are already on the hpts? */
panic("%s: hpts:%p inp:%p already on the hpts?", __FUNCTION__, hpts, inp);
}
#endif
TAILQ_INSERT_TAIL(head, inp, inp_hpts);
inp->inp_in_hpts = 1;
hpts->p_on_queue_cnt++;
if (noref == 0) {
in_pcbref(inp);
}
}
static inline void
hpts_sane_input_remove(struct tcp_hpts_entry *hpts, struct inpcb *inp, int clear)
{
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx) == 0) {
/* We don't own the mutex? */
panic("%s: hpts:%p inp:%p no hpts mutex", __FUNCTION__, hpts, inp);
}
if (hpts->p_cpu != inp->inp_input_cpu) {
/* It is not the right cpu/mutex? */
panic("%s: hpts:%p inp:%p incorrect CPU", __FUNCTION__, hpts, inp);
}
if (inp->inp_in_input == 0) {
/* We are not on the input hpts? */
panic("%s: hpts:%p inp:%p not on the input hpts?", __FUNCTION__, hpts, inp);
}
#endif
TAILQ_REMOVE(&hpts->p_input, inp, inp_input);
hpts->p_on_inqueue_cnt--;
if (hpts->p_on_inqueue_cnt < 0) {
#ifdef INVARIANTS
panic("Hpts in goes negative inp:%p hpts:%p",
inp, hpts);
#endif
hpts->p_on_inqueue_cnt = 0;
}
#ifdef INVARIANTS
if (TAILQ_EMPTY(&hpts->p_input) &&
(hpts->p_on_inqueue_cnt != 0)) {
/* We should not be empty with a queue count */
panic("%s hpts:%p in_hpts input empty but cnt:%d",
__FUNCTION__, hpts, hpts->p_on_inqueue_cnt);
}
#endif
if (clear)
inp->inp_in_input = 0;
}
static inline void
hpts_sane_input_insert(struct tcp_hpts_entry *hpts, struct inpcb *inp, int line)
{
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx) == 0) {
/* We don't own the mutex? */
panic("%s: hpts:%p inp:%p no hpts mutex", __FUNCTION__, hpts, inp);
}
if (hpts->p_cpu != inp->inp_input_cpu) {
/* It is not the right cpu/mutex? */
panic("%s: hpts:%p inp:%p incorrect CPU", __FUNCTION__, hpts, inp);
}
if (inp->inp_in_input == 1) {
/* We are already on the input hpts? */
panic("%s: hpts:%p inp:%p already on the input hpts?", __FUNCTION__, hpts, inp);
}
#endif
TAILQ_INSERT_TAIL(&hpts->p_input, inp, inp_input);
inp->inp_in_input = 1;
hpts->p_on_inqueue_cnt++;
in_pcbref(inp);
}
static int
sysctl_tcp_hpts_log(SYSCTL_HANDLER_ARGS)
{
struct tcp_hpts_entry *hpts;
size_t sz;
int32_t logging_was, i;
int32_t error = 0;
/*
* HACK: Turn off logging so no locks are required this really needs
* a memory barrier :)
*/
logging_was = logging_on;
logging_on = 0;
if (!req->oldptr) {
/* How much? */
sz = 0;
for (i = 0; i < tcp_pace.rp_num_hptss; i++) {
hpts = tcp_pace.rp_ent[i];
if (hpts->p_log == NULL)
continue;
sz += (sizeof(struct hpts_log) * hpts->p_logsize);
}
error = SYSCTL_OUT(req, 0, sz);
} else {
for (i = 0; i < tcp_pace.rp_num_hptss; i++) {
hpts = tcp_pace.rp_ent[i];
if (hpts->p_log == NULL)
continue;
if (hpts->p_log_wrapped)
sz = (sizeof(struct hpts_log) * hpts->p_logsize);
else
sz = (sizeof(struct hpts_log) * hpts->p_log_at);
error = SYSCTL_OUT(req, hpts->p_log, sz);
}
}
logging_on = logging_was;
return error;
}
SYSCTL_PROC(_net_inet_tcp_hpts, OID_AUTO, log, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
0, 0, sysctl_tcp_hpts_log, "A", "tcp hptsi log");
/*
* Try to get the INP_INFO lock.
*
* This function always succeeds in getting the lock. It will clear
* *tpp and return (1) if something critical changed while the inpcb
* was unlocked. Otherwise, it will leave *tpp unchanged and return (0).
*
* This function relies on the fact that the hpts always holds a
* reference on the inpcb while the segment is on the hptsi wheel and
* in the input queue.
*
*/
static int
tcp_hptsi_lock_inpinfo(struct inpcb *inp, struct tcpcb **tpp)
{
struct tcp_function_block *tfb;
struct tcpcb *tp;
void *ptr;
/* Try the easy way. */
if (INP_INFO_TRY_RLOCK(&V_tcbinfo))
return (0);
/*
* OK, let's try the hard way. We'll save the function pointer block
* to make sure that doesn't change while we aren't holding the
* lock.
*/
tp = *tpp;
tfb = tp->t_fb;
ptr = tp->t_fb_ptr;
INP_WUNLOCK(inp);
INP_INFO_RLOCK(&V_tcbinfo);
INP_WLOCK(inp);
/* If the session went away, return an error. */
if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) ||
(inp->inp_flags2 & INP_FREED)) {
*tpp = NULL;
return (1);
}
/*
* If the function block or stack-specific data block changed,
* report an error.
*/
tp = intotcpcb(inp);
if ((tp->t_fb != tfb) && (tp->t_fb_ptr != ptr)) {
*tpp = NULL;
return (1);
}
return (0);
}
static void
tcp_wakehpts(struct tcp_hpts_entry *hpts)
{
HPTS_MTX_ASSERT(hpts);
swi_sched(hpts->ie_cookie, 0);
if (hpts->p_hpts_active == 2) {
/* Rare sleeping on a ENOBUF */
wakeup_one(hpts);
}
}
static void
tcp_wakeinput(struct tcp_hpts_entry *hpts)
{
HPTS_MTX_ASSERT(hpts);
swi_sched(hpts->ie_cookie, 0);
if (hpts->p_hpts_active == 2) {
/* Rare sleeping on a ENOBUF */
wakeup_one(hpts);
}
}
struct tcp_hpts_entry *
tcp_cur_hpts(struct inpcb *inp)
{
int32_t hpts_num;
struct tcp_hpts_entry *hpts;
hpts_num = inp->inp_hpts_cpu;
hpts = tcp_pace.rp_ent[hpts_num];
return (hpts);
}
struct tcp_hpts_entry *
tcp_hpts_lock(struct inpcb *inp)
{
struct tcp_hpts_entry *hpts;
int32_t hpts_num;
again:
hpts_num = inp->inp_hpts_cpu;
hpts = tcp_pace.rp_ent[hpts_num];
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx)) {
panic("Hpts:%p owns mtx prior-to lock line:%d",
hpts, __LINE__);
}
#endif
mtx_lock(&hpts->p_mtx);
if (hpts_num != inp->inp_hpts_cpu) {
mtx_unlock(&hpts->p_mtx);
goto again;
}
return (hpts);
}
struct tcp_hpts_entry *
tcp_input_lock(struct inpcb *inp)
{
struct tcp_hpts_entry *hpts;
int32_t hpts_num;
again:
hpts_num = inp->inp_input_cpu;
hpts = tcp_pace.rp_ent[hpts_num];
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx)) {
panic("Hpts:%p owns mtx prior-to lock line:%d",
hpts, __LINE__);
}
#endif
mtx_lock(&hpts->p_mtx);
if (hpts_num != inp->inp_input_cpu) {
mtx_unlock(&hpts->p_mtx);
goto again;
}
return (hpts);
}
static void
tcp_remove_hpts_ref(struct inpcb *inp, struct tcp_hpts_entry *hpts, int line)
{
int32_t add_freed;
if (inp->inp_flags2 & INP_FREED) {
/*
* Need to play a special trick so that in_pcbrele_wlocked
* does not return 1 when it really should have returned 0.
*/
add_freed = 1;
inp->inp_flags2 &= ~INP_FREED;
} else {
add_freed = 0;
}
#ifndef INP_REF_DEBUG
if (in_pcbrele_wlocked(inp)) {
/*
* This should not happen. We have the inpcb referred to by
* the main socket (why we are called) and the hpts. It
* should always return 0.
*/
panic("inpcb:%p release ret 1",
inp);
}
#else
if (__in_pcbrele_wlocked(inp, line)) {
/*
* This should not happen. We have the inpcb referred to by
* the main socket (why we are called) and the hpts. It
* should always return 0.
*/
panic("inpcb:%p release ret 1",
inp);
}
#endif
if (add_freed) {
inp->inp_flags2 |= INP_FREED;
}
}
static void
tcp_hpts_remove_locked_output(struct tcp_hpts_entry *hpts, struct inpcb *inp, int32_t flags, int32_t line)
{
if (inp->inp_in_hpts) {
hpts_sane_pace_remove(hpts, inp, &hpts->p_hptss[inp->inp_hptsslot], 1);
tcp_remove_hpts_ref(inp, hpts, line);
}
}
static void
tcp_hpts_remove_locked_input(struct tcp_hpts_entry *hpts, struct inpcb *inp, int32_t flags, int32_t line)
{
HPTS_MTX_ASSERT(hpts);
if (inp->inp_in_input) {
hpts_sane_input_remove(hpts, inp, 1);
tcp_remove_hpts_ref(inp, hpts, line);
}
}
/*
* Called normally with the INP_LOCKED but it
* does not matter, the hpts lock is the key
* but the lock order allows us to hold the
* INP lock and then get the hpts lock.
*
* Valid values in the flags are
* HPTS_REMOVE_OUTPUT - remove from the output of the hpts.
* HPTS_REMOVE_INPUT - remove from the input of the hpts.
* Note that you can or both values together and get two
* actions.
*/
void
__tcp_hpts_remove(struct inpcb *inp, int32_t flags, int32_t line)
{
struct tcp_hpts_entry *hpts;
INP_WLOCK_ASSERT(inp);
if (flags & HPTS_REMOVE_OUTPUT) {
hpts = tcp_hpts_lock(inp);
tcp_hpts_remove_locked_output(hpts, inp, flags, line);
mtx_unlock(&hpts->p_mtx);
}
if (flags & HPTS_REMOVE_INPUT) {
hpts = tcp_input_lock(inp);
tcp_hpts_remove_locked_input(hpts, inp, flags, line);
mtx_unlock(&hpts->p_mtx);
}
}
static inline int
hpts_tick(struct tcp_hpts_entry *hpts, int32_t plus)
{
return ((hpts->p_prevtick + plus) % NUM_OF_HPTSI_SLOTS);
}
static int
tcp_queue_to_hpts_immediate_locked(struct inpcb *inp, struct tcp_hpts_entry *hpts, int32_t line, int32_t noref)
{
int32_t need_wake = 0;
uint32_t ticknow = 0;
HPTS_MTX_ASSERT(hpts);
if (inp->inp_in_hpts == 0) {
/* Ok we need to set it on the hpts in the current slot */
if (hpts->p_hpts_active == 0) {
/* A sleeping hpts we want in next slot to run */
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_INSERT_SLEEPER, 0,
hpts_tick(hpts, 1));
}
inp->inp_hptsslot = hpts_tick(hpts, 1);
inp->inp_hpts_request = 0;
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_SLEEP_BEFORE, 1, ticknow);
}
need_wake = 1;
} else if ((void *)inp == hpts->p_inp) {
/*
* We can't allow you to go into the same slot we
* are in. We must put you out.
*/
inp->inp_hptsslot = hpts->p_nxt_slot;
} else
inp->inp_hptsslot = hpts->p_cur_slot;
hpts_sane_pace_insert(hpts, inp, &hpts->p_hptss[inp->inp_hptsslot], line, noref);
inp->inp_hpts_request = 0;
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_IMMEDIATE, 0, 0);
}
if (need_wake) {
/*
* Activate the hpts if it is sleeping and its
* timeout is not 1.
*/
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_WAKEUP_HPTS, 0, ticknow);
}
hpts->p_direct_wake = 1;
tcp_wakehpts(hpts);
}
}
return (need_wake);
}
int
__tcp_queue_to_hpts_immediate(struct inpcb *inp, int32_t line)
{
int32_t ret;
struct tcp_hpts_entry *hpts;
INP_WLOCK_ASSERT(inp);
hpts = tcp_hpts_lock(inp);
ret = tcp_queue_to_hpts_immediate_locked(inp, hpts, line, 0);
mtx_unlock(&hpts->p_mtx);
return (ret);
}
static void
tcp_hpts_insert_locked(struct tcp_hpts_entry *hpts, struct inpcb *inp, uint32_t slot, uint32_t cts, int32_t line,
struct hpts_diag *diag, int32_t noref)
{
int32_t need_new_to = 0;
int32_t need_wakeup = 0;
uint32_t largest_slot;
uint32_t ticknow = 0;
uint32_t slot_calc;
HPTS_MTX_ASSERT(hpts);
if (diag) {
memset(diag, 0, sizeof(struct hpts_diag));
diag->p_hpts_active = hpts->p_hpts_active;
diag->p_nxt_slot = hpts->p_nxt_slot;
diag->p_cur_slot = hpts->p_cur_slot;
diag->slot_req = slot;
}
if ((inp->inp_in_hpts == 0) || noref) {
inp->inp_hpts_request = slot;
if (slot == 0) {
/* Immediate */
tcp_queue_to_hpts_immediate_locked(inp, hpts, line, noref);
return;
}
if (hpts->p_hpts_active) {
/*
* Its slot - 1 since nxt_slot is the next tick that
* will go off since the hpts is awake
*/
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_INSERT_NORMAL, slot, 0);
}
/*
* We want to make sure that we don't place a inp in
* the range of p_cur_slot <-> p_nxt_slot. If we
* take from p_nxt_slot to the end, plus p_cur_slot
* and then take away 2, we will know how many is
* the max slots we can use.
*/
if (hpts->p_nxt_slot > hpts->p_cur_slot) {
/*
* Non-wrap case nxt_slot <-> cur_slot we
* don't want to land in. So the diff gives
* us what is taken away from the number of
* slots.
*/
largest_slot = NUM_OF_HPTSI_SLOTS - (hpts->p_nxt_slot - hpts->p_cur_slot);
} else if (hpts->p_nxt_slot == hpts->p_cur_slot) {
largest_slot = NUM_OF_HPTSI_SLOTS - 2;
} else {
/*
* Wrap case so the diff gives us the number
* of slots that we can land in.
*/
largest_slot = hpts->p_cur_slot - hpts->p_nxt_slot;
}
/*
* We take away two so we never have a problem (20
* usec's) out of 1024000 usecs
*/
largest_slot -= 2;
if (inp->inp_hpts_request > largest_slot) {
/*
* Restrict max jump of slots and remember
* leftover
*/
slot = largest_slot;
inp->inp_hpts_request -= largest_slot;
} else {
/* This one will run when we hit it */
inp->inp_hpts_request = 0;
}
if (hpts->p_nxt_slot == hpts->p_cur_slot)
slot_calc = (hpts->p_nxt_slot + slot) % NUM_OF_HPTSI_SLOTS;
else
slot_calc = (hpts->p_nxt_slot + slot - 1) % NUM_OF_HPTSI_SLOTS;
if (slot_calc == hpts->p_cur_slot) {
#ifdef INVARIANTS
/* TSNH */
panic("Hpts:%p impossible slot calculation slot_calc:%u slot:%u largest:%u\n",
hpts, slot_calc, slot, largest_slot);
#endif
if (slot_calc)
slot_calc--;
else
slot_calc = NUM_OF_HPTSI_SLOTS - 1;
}
inp->inp_hptsslot = slot_calc;
if (diag) {
diag->inp_hptsslot = inp->inp_hptsslot;
}
} else {
/*
* The hpts is sleeping, we need to figure out where
* it will wake up at and if we need to reschedule
* its time-out.
*/
uint32_t have_slept, yet_to_sleep;
uint32_t slot_now;
struct timeval tv;
ticknow = tcp_gethptstick(&tv);
slot_now = ticknow % NUM_OF_HPTSI_SLOTS;
/*
* The user wants to be inserted at (slot_now +
* slot) % NUM_OF_HPTSI_SLOTS, so lets set that up.
*/
largest_slot = NUM_OF_HPTSI_SLOTS - 2;
if (inp->inp_hpts_request > largest_slot) {
/* Adjust the residual in inp_hpts_request */
slot = largest_slot;
inp->inp_hpts_request -= largest_slot;
} else {
/* No residual it all fits */
inp->inp_hpts_request = 0;
}
inp->inp_hptsslot = (slot_now + slot) % NUM_OF_HPTSI_SLOTS;
if (diag) {
diag->slot_now = slot_now;
diag->inp_hptsslot = inp->inp_hptsslot;
diag->p_on_min_sleep = hpts->p_on_min_sleep;
}
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_INSERT_SLEEPER, slot, ticknow);
}
/* Now do we need to restart the hpts's timer? */
if (TSTMP_GT(ticknow, hpts->p_curtick))
have_slept = ticknow - hpts->p_curtick;
else
have_slept = 0;
if (have_slept < hpts->p_hpts_sleep_time) {
/* This should be what happens */
yet_to_sleep = hpts->p_hpts_sleep_time - have_slept;
} else {
/* We are over-due */
yet_to_sleep = 0;
need_wakeup = 1;
}
if (diag) {
diag->have_slept = have_slept;
diag->yet_to_sleep = yet_to_sleep;
diag->hpts_sleep_time = hpts->p_hpts_sleep_time;
}
if ((hpts->p_on_min_sleep == 0) && (yet_to_sleep > slot)) {
/*
* We need to reschedule the hptss time-out.
*/
hpts->p_hpts_sleep_time = slot;
need_new_to = slot * HPTS_TICKS_PER_USEC;
}
}
hpts_sane_pace_insert(hpts, inp, &hpts->p_hptss[inp->inp_hptsslot], line, noref);
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_INSERTED, slot, ticknow);
}
/*
* Now how far is the hpts sleeping to? if active is 1, its
* up and ticking we do nothing, otherwise we may need to
* reschedule its callout if need_new_to is set from above.
*/
if (need_wakeup) {
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_RESCHEDULE, 1, 0);
}
hpts->p_direct_wake = 1;
tcp_wakehpts(hpts);
if (diag) {
diag->need_new_to = 0;
diag->co_ret = 0xffff0000;
}
} else if (need_new_to) {
int32_t co_ret;
struct timeval tv;
sbintime_t sb;
tv.tv_sec = 0;
tv.tv_usec = 0;
while (need_new_to > HPTS_USEC_IN_SEC) {
tv.tv_sec++;
need_new_to -= HPTS_USEC_IN_SEC;
}
tv.tv_usec = need_new_to;
sb = tvtosbt(tv);
if (tcp_hpts_callout_skip_swi == 0) {
co_ret = callout_reset_sbt_on(&hpts->co, sb, 0,
hpts_timeout_swi, hpts, hpts->p_cpu,
(C_DIRECT_EXEC | C_PREL(tcp_hpts_precision)));
} else {
co_ret = callout_reset_sbt_on(&hpts->co, sb, 0,
hpts_timeout_dir, hpts,
hpts->p_cpu,
C_PREL(tcp_hpts_precision));
}
if (diag) {
diag->need_new_to = need_new_to;
diag->co_ret = co_ret;
}
}
} else {
#ifdef INVARIANTS
panic("Hpts:%p tp:%p already on hpts and add?", hpts, inp);
#endif
}
}
uint32_t
tcp_hpts_insert_diag(struct inpcb *inp, uint32_t slot, int32_t line, struct hpts_diag *diag){
struct tcp_hpts_entry *hpts;
uint32_t slot_on, cts;
struct timeval tv;
/*
* We now return the next-slot the hpts will be on, beyond its
* current run (if up) or where it was when it stopped if it is
* sleeping.
*/
INP_WLOCK_ASSERT(inp);
hpts = tcp_hpts_lock(inp);
if (in_ts_percision)
microuptime(&tv);
else
getmicrouptime(&tv);
cts = tcp_tv_to_usectick(&tv);
tcp_hpts_insert_locked(hpts, inp, slot, cts, line, diag, 0);
slot_on = hpts->p_nxt_slot;
mtx_unlock(&hpts->p_mtx);
return (slot_on);
}
uint32_t
__tcp_hpts_insert(struct inpcb *inp, uint32_t slot, int32_t line){
return (tcp_hpts_insert_diag(inp, slot, line, NULL));
}
int
__tcp_queue_to_input_locked(struct inpcb *inp, struct tcp_hpts_entry *hpts, int32_t line)
{
int32_t retval = 0;
HPTS_MTX_ASSERT(hpts);
if (inp->inp_in_input == 0) {
/* Ok we need to set it on the hpts in the current slot */
hpts_sane_input_insert(hpts, inp, line);
retval = 1;
if (hpts->p_hpts_active == 0) {
/*
* Activate the hpts if it is sleeping.
*/
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_WAKEUP_INPUT, 0, 0);
}
retval = 2;
hpts->p_direct_wake = 1;
tcp_wakeinput(hpts);
}
} else if (hpts->p_hpts_active == 0) {
retval = 4;
hpts->p_direct_wake = 1;
tcp_wakeinput(hpts);
}
return (retval);
}
void
tcp_queue_pkt_to_input(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
int32_t tlen, int32_t drop_hdrlen, uint8_t iptos, uint8_t ti_locked)
{
/* Setup packet for input first */
INP_WLOCK_ASSERT(tp->t_inpcb);
m->m_pkthdr.pace_thoff = (uint16_t) ((caddr_t)th - mtod(m, caddr_t));
m->m_pkthdr.pace_tlen = (uint16_t) tlen;
m->m_pkthdr.pace_drphdrlen = drop_hdrlen;
m->m_pkthdr.pace_tos = iptos;
m->m_pkthdr.pace_lock = (uint8_t) ti_locked;
if (tp->t_in_pkt == NULL) {
tp->t_in_pkt = m;
tp->t_tail_pkt = m;
} else {
tp->t_tail_pkt->m_nextpkt = m;
tp->t_tail_pkt = m;
}
}
int32_t
__tcp_queue_to_input(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
int32_t tlen, int32_t drop_hdrlen, uint8_t iptos, uint8_t ti_locked, int32_t line){
struct tcp_hpts_entry *hpts;
int32_t ret;
tcp_queue_pkt_to_input(tp, m, th, tlen, drop_hdrlen, iptos, ti_locked);
hpts = tcp_input_lock(tp->t_inpcb);
ret = __tcp_queue_to_input_locked(tp->t_inpcb, hpts, line);
mtx_unlock(&hpts->p_mtx);
return (ret);
}
void
__tcp_set_inp_to_drop(struct inpcb *inp, uint16_t reason, int32_t line)
{
struct tcp_hpts_entry *hpts;
struct tcpcb *tp;
tp = intotcpcb(inp);
hpts = tcp_input_lock(tp->t_inpcb);
if (inp->inp_in_input == 0) {
/* Ok we need to set it on the hpts in the current slot */
hpts_sane_input_insert(hpts, inp, line);
if (hpts->p_hpts_active == 0) {
/*
* Activate the hpts if it is sleeping.
*/
hpts->p_direct_wake = 1;
tcp_wakeinput(hpts);
}
} else if (hpts->p_hpts_active == 0) {
hpts->p_direct_wake = 1;
tcp_wakeinput(hpts);
}
inp->inp_hpts_drop_reas = reason;
mtx_unlock(&hpts->p_mtx);
}
static uint16_t
hpts_random_cpu(struct inpcb *inp){
/*
* No flow type set distribute the load randomly.
*/
uint16_t cpuid;
uint32_t ran;
/*
* If one has been set use it i.e. we want both in and out on the
* same hpts.
*/
if (inp->inp_input_cpu_set) {
return (inp->inp_input_cpu);
} else if (inp->inp_hpts_cpu_set) {
return (inp->inp_hpts_cpu);
}
/* Nothing set use a random number */
ran = arc4random();
cpuid = (ran & 0xffff) % mp_ncpus;
return (cpuid);
}
static uint16_t
hpts_cpuid(struct inpcb *inp){
uint16_t cpuid;
/*
* If one has been set use it i.e. we want both in and out on the
* same hpts.
*/
if (inp->inp_input_cpu_set) {
return (inp->inp_input_cpu);
} else if (inp->inp_hpts_cpu_set) {
return (inp->inp_hpts_cpu);
}
/* If one is set the other must be the same */
#ifdef RSS
cpuid = rss_hash2cpuid(inp->inp_flowid, inp->inp_flowtype);
if (cpuid == NETISR_CPUID_NONE)
return (hpts_random_cpu(inp));
else
return (cpuid);
#else
/*
* We don't have a flowid -> cpuid mapping, so cheat and just map
* unknown cpuids to curcpu. Not the best, but apparently better
* than defaulting to swi 0.
*/
if (inp->inp_flowtype != M_HASHTYPE_NONE) {
cpuid = inp->inp_flowid % mp_ncpus;
return (cpuid);
}
cpuid = hpts_random_cpu(inp);
return (cpuid);
#endif
}
/*
* Do NOT try to optimize the processing of inp's
* by first pulling off all the inp's into a temporary
* list (e.g. TAILQ_CONCAT). If you do that the subtle
* interactions of switching CPU's will kill because of
* problems in the linked list manipulation. Basically
* you would switch cpu's with the hpts mutex locked
* but then while you were processing one of the inp's
* some other one that you switch will get a new
* packet on the different CPU. It will insert it
* on the new hptss input list. Creating a temporary
* link in the inp will not fix it either, since
* the other hpts will be doing the same thing and
* you will both end up using the temporary link.
*
* You will die in an ASSERT for tailq corruption if you
* run INVARIANTS or you will die horribly without
* INVARIANTS in some unknown way with a corrupt linked
* list.
*/
static void
tcp_input_data(struct tcp_hpts_entry *hpts, struct timeval *tv)
{
struct mbuf *m, *n;
struct tcpcb *tp;
struct inpcb *inp;
uint16_t drop_reason;
int16_t set_cpu;
uint32_t did_prefetch = 0;
int32_t ti_locked = TI_UNLOCKED;
HPTS_MTX_ASSERT(hpts);
while ((inp = TAILQ_FIRST(&hpts->p_input)) != NULL) {
HPTS_MTX_ASSERT(hpts);
hpts_sane_input_remove(hpts, inp, 0);
if (inp->inp_input_cpu_set == 0) {
set_cpu = 1;
} else {
set_cpu = 0;
}
hpts->p_inp = inp;
drop_reason = inp->inp_hpts_drop_reas;
inp->inp_in_input = 0;
mtx_unlock(&hpts->p_mtx);
if (drop_reason) {
INP_INFO_RLOCK(&V_tcbinfo);
ti_locked = TI_RLOCKED;
} else {
ti_locked = TI_UNLOCKED;
}
INP_WLOCK(inp);
if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) ||
(inp->inp_flags2 & INP_FREED)) {
out:
hpts->p_inp = NULL;
if (ti_locked == TI_RLOCKED) {
INP_INFO_RUNLOCK(&V_tcbinfo);
}
if (in_pcbrele_wlocked(inp) == 0) {
INP_WUNLOCK(inp);
}
ti_locked = TI_UNLOCKED;
mtx_lock(&hpts->p_mtx);
continue;
}
tp = intotcpcb(inp);
if ((tp == NULL) || (tp->t_inpcb == NULL)) {
goto out;
}
if (drop_reason) {
/* This tcb is being destroyed for drop_reason */
m = tp->t_in_pkt;
if (m)
n = m->m_nextpkt;
else
n = NULL;
tp->t_in_pkt = NULL;
while (m) {
m_freem(m);
m = n;
if (m)
n = m->m_nextpkt;
}
tp = tcp_drop(tp, drop_reason);
INP_INFO_RUNLOCK(&V_tcbinfo);
if (tp == NULL) {
INP_WLOCK(inp);
}
if (in_pcbrele_wlocked(inp) == 0)
INP_WUNLOCK(inp);
mtx_lock(&hpts->p_mtx);
continue;
}
if (set_cpu) {
/*
* Setup so the next time we will move to the right
* CPU. This should be a rare event. It will
* sometimes happens when we are the client side
* (usually not the server). Somehow tcp_output()
* gets called before the tcp_do_segment() sets the
* intial state. This means the r_cpu and r_hpts_cpu
* is 0. We get on the hpts, and then tcp_input()
* gets called setting up the r_cpu to the correct
* value. The hpts goes off and sees the mis-match.
* We simply correct it here and the CPU will switch
* to the new hpts nextime the tcb gets added to the
* the hpts (not this time) :-)
*/
tcp_set_hpts(inp);
}
CURVNET_SET(tp->t_vnet);
m = tp->t_in_pkt;
n = NULL;
if (m != NULL &&
(m->m_pkthdr.pace_lock == TI_RLOCKED ||
tp->t_state != TCPS_ESTABLISHED)) {
ti_locked = TI_RLOCKED;
if (tcp_hptsi_lock_inpinfo(inp, &tp)) {
CURVNET_RESTORE();
goto out;
}
m = tp->t_in_pkt;
}
if (in_newts_every_tcb) {
if (in_ts_percision)
microuptime(tv);
else
getmicrouptime(tv);
}
if (tp->t_fb_ptr != NULL) {
kern_prefetch(tp->t_fb_ptr, &did_prefetch);
did_prefetch = 1;
}
/* Any input work to do, if so do it first */
if ((m != NULL) && (m == tp->t_in_pkt)) {
struct tcphdr *th;
int32_t tlen, drop_hdrlen, nxt_pkt;
uint8_t iptos;
n = m->m_nextpkt;
tp->t_in_pkt = tp->t_tail_pkt = NULL;
while (m) {
th = (struct tcphdr *)(mtod(m, caddr_t)+m->m_pkthdr.pace_thoff);
tlen = m->m_pkthdr.pace_tlen;
drop_hdrlen = m->m_pkthdr.pace_drphdrlen;
iptos = m->m_pkthdr.pace_tos;
m->m_nextpkt = NULL;
if (n)
nxt_pkt = 1;
else
nxt_pkt = 0;
inp->inp_input_calls = 1;
if (tp->t_fb->tfb_tcp_hpts_do_segment) {
/* Use the hpts specific do_segment */
(*tp->t_fb->tfb_tcp_hpts_do_segment) (m, th, inp->inp_socket,
tp, drop_hdrlen,
tlen, iptos, ti_locked, nxt_pkt, tv);
} else {
/* Use the default do_segment */
(*tp->t_fb->tfb_tcp_do_segment) (m, th, inp->inp_socket,
tp, drop_hdrlen,
tlen, iptos, ti_locked);
}
/*
* Do segment returns unlocked we need the
* lock again but we also need some kasserts
* here.
*/
INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
INP_UNLOCK_ASSERT(inp);
m = n;
if (m)
n = m->m_nextpkt;
if (m != NULL &&
m->m_pkthdr.pace_lock == TI_RLOCKED) {
INP_INFO_RLOCK(&V_tcbinfo);
ti_locked = TI_RLOCKED;
} else
ti_locked = TI_UNLOCKED;
INP_WLOCK(inp);
/*
* Since we have an opening here we must
* re-check if the tcb went away while we
* were getting the lock(s).
*/
if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) ||
(inp->inp_flags2 & INP_FREED)) {
out_free:
while (m) {
m_freem(m);
m = n;
if (m)
n = m->m_nextpkt;
}
CURVNET_RESTORE();
goto out;
}
/*
* Now that we hold the INP lock, check if
* we need to upgrade our lock.
*/
if (ti_locked == TI_UNLOCKED &&
(tp->t_state != TCPS_ESTABLISHED)) {
ti_locked = TI_RLOCKED;
if (tcp_hptsi_lock_inpinfo(inp, &tp))
goto out_free;
}
} /** end while(m) */
} /** end if ((m != NULL) && (m == tp->t_in_pkt)) */
if (in_pcbrele_wlocked(inp) == 0)
INP_WUNLOCK(inp);
if (ti_locked == TI_RLOCKED)
INP_INFO_RUNLOCK(&V_tcbinfo);
INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
INP_UNLOCK_ASSERT(inp);
ti_locked = TI_UNLOCKED;
mtx_lock(&hpts->p_mtx);
hpts->p_inp = NULL;
CURVNET_RESTORE();
}
}
static int
tcp_hpts_est_run(struct tcp_hpts_entry *hpts)
{
int32_t ticks_to_run;
if (hpts->p_prevtick && (SEQ_GT(hpts->p_curtick, hpts->p_prevtick))) {
ticks_to_run = hpts->p_curtick - hpts->p_prevtick;
if (ticks_to_run >= (NUM_OF_HPTSI_SLOTS - 1)) {
ticks_to_run = NUM_OF_HPTSI_SLOTS - 2;
}
} else {
if (hpts->p_prevtick == hpts->p_curtick) {
/* This happens when we get woken up right away */
return (-1);
}
ticks_to_run = 1;
}
/* Set in where we will be when we catch up */
hpts->p_nxt_slot = (hpts->p_cur_slot + ticks_to_run) % NUM_OF_HPTSI_SLOTS;
if (hpts->p_nxt_slot == hpts->p_cur_slot) {
panic("Impossible math -- hpts:%p p_nxt_slot:%d p_cur_slot:%d ticks_to_run:%d",
hpts, hpts->p_nxt_slot, hpts->p_cur_slot, ticks_to_run);
}
return (ticks_to_run);
}
static void
tcp_hptsi(struct tcp_hpts_entry *hpts, struct timeval *ctick)
{
struct tcpcb *tp;
struct inpcb *inp = NULL, *ninp;
struct timeval tv;
int32_t ticks_to_run, i, error, tick_now, interum_tick;
int32_t paced_cnt = 0;
int32_t did_prefetch = 0;
int32_t prefetch_ninp = 0;
int32_t prefetch_tp = 0;
uint32_t cts;
int16_t set_cpu;
HPTS_MTX_ASSERT(hpts);
hpts->p_curtick = tcp_tv_to_hptstick(ctick);
cts = tcp_tv_to_usectick(ctick);
memcpy(&tv, ctick, sizeof(struct timeval));
hpts->p_cur_slot = hpts_tick(hpts, 1);
/* Figure out if we had missed ticks */
again:
HPTS_MTX_ASSERT(hpts);
ticks_to_run = tcp_hpts_est_run(hpts);
if (!TAILQ_EMPTY(&hpts->p_input)) {
tcp_input_data(hpts, &tv);
}
#ifdef INVARIANTS
if (TAILQ_EMPTY(&hpts->p_input) &&
(hpts->p_on_inqueue_cnt != 0)) {
panic("tp:%p in_hpts input empty but cnt:%d",
hpts, hpts->p_on_inqueue_cnt);
}
#endif
HPTS_MTX_ASSERT(hpts);
/* Reset the ticks to run and time if we need too */
interum_tick = tcp_gethptstick(&tv);
if (interum_tick != hpts->p_curtick) {
/* Save off the new time we execute to */
*ctick = tv;
hpts->p_curtick = interum_tick;
cts = tcp_tv_to_usectick(&tv);
hpts->p_cur_slot = hpts_tick(hpts, 1);
ticks_to_run = tcp_hpts_est_run(hpts);
}
if (ticks_to_run == -1) {
goto no_run;
}
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_SETTORUN, ticks_to_run, 0);
}
if (hpts->p_on_queue_cnt == 0) {
goto no_one;
}
HPTS_MTX_ASSERT(hpts);
for (i = 0; i < ticks_to_run; i++) {
/*
* Calculate our delay, if there are no extra ticks there
* was not any
*/
hpts->p_delayed_by = (ticks_to_run - (i + 1)) * HPTS_TICKS_PER_USEC;
HPTS_MTX_ASSERT(hpts);
while ((inp = TAILQ_FIRST(&hpts->p_hptss[hpts->p_cur_slot])) != NULL) {
/* For debugging */
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_HPTSI, ticks_to_run, i);
}
hpts->p_inp = inp;
paced_cnt++;
if (hpts->p_cur_slot != inp->inp_hptsslot) {
panic("Hpts:%p inp:%p slot mis-aligned %u vs %u",
hpts, inp, hpts->p_cur_slot, inp->inp_hptsslot);
}
/* Now pull it */
if (inp->inp_hpts_cpu_set == 0) {
set_cpu = 1;
} else {
set_cpu = 0;
}
hpts_sane_pace_remove(hpts, inp, &hpts->p_hptss[hpts->p_cur_slot], 0);
if ((ninp = TAILQ_FIRST(&hpts->p_hptss[hpts->p_cur_slot])) != NULL) {
/* We prefetch the next inp if possible */
kern_prefetch(ninp, &prefetch_ninp);
prefetch_ninp = 1;
}
if (inp->inp_hpts_request) {
/*
* This guy is deferred out further in time
* then our wheel had on it. Push him back
* on the wheel.
*/
int32_t remaining_slots;
remaining_slots = ticks_to_run - (i + 1);
if (inp->inp_hpts_request > remaining_slots) {
/*
* Keep INVARIANTS happy by clearing
* the flag
*/
tcp_hpts_insert_locked(hpts, inp, inp->inp_hpts_request, cts, __LINE__, NULL, 1);
hpts->p_inp = NULL;
continue;
}
inp->inp_hpts_request = 0;
}
/*
* We clear the hpts flag here after dealing with
* remaining slots. This way anyone looking with the
* TCB lock will see its on the hpts until just
* before we unlock.
*/
inp->inp_in_hpts = 0;
mtx_unlock(&hpts->p_mtx);
INP_WLOCK(inp);
if (in_pcbrele_wlocked(inp)) {
mtx_lock(&hpts->p_mtx);
if (logging_on)
tcp_hpts_log_it(hpts, hpts->p_inp, HPTSLOG_INP_DONE, 0, 1);
hpts->p_inp = NULL;
continue;
}
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
out_now:
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx)) {
panic("Hpts:%p owns mtx prior-to lock line:%d",
hpts, __LINE__);
}
#endif
INP_WUNLOCK(inp);
mtx_lock(&hpts->p_mtx);
if (logging_on)
tcp_hpts_log_it(hpts, hpts->p_inp, HPTSLOG_INP_DONE, 0, 3);
hpts->p_inp = NULL;
continue;
}
tp = intotcpcb(inp);
if ((tp == NULL) || (tp->t_inpcb == NULL)) {
goto out_now;
}
if (set_cpu) {
/*
* Setup so the next time we will move to
* the right CPU. This should be a rare
* event. It will sometimes happens when we
* are the client side (usually not the
* server). Somehow tcp_output() gets called
* before the tcp_do_segment() sets the
* intial state. This means the r_cpu and
* r_hpts_cpu is 0. We get on the hpts, and
* then tcp_input() gets called setting up
* the r_cpu to the correct value. The hpts
* goes off and sees the mis-match. We
* simply correct it here and the CPU will
* switch to the new hpts nextime the tcb
* gets added to the the hpts (not this one)
* :-)
*/
tcp_set_hpts(inp);
}
if (out_newts_every_tcb) {
struct timeval sv;
if (out_ts_percision)
microuptime(&sv);
else
getmicrouptime(&sv);
cts = tcp_tv_to_usectick(&sv);
}
CURVNET_SET(tp->t_vnet);
/*
* There is a hole here, we get the refcnt on the
* inp so it will still be preserved but to make
* sure we can get the INP we need to hold the p_mtx
* above while we pull out the tp/inp, as long as
* fini gets the lock first we are assured of having
* a sane INP we can lock and test.
*/
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx)) {
panic("Hpts:%p owns mtx before tcp-output:%d",
hpts, __LINE__);
}
#endif
if (tp->t_fb_ptr != NULL) {
kern_prefetch(tp->t_fb_ptr, &did_prefetch);
did_prefetch = 1;
}
inp->inp_hpts_calls = 1;
if (tp->t_fb->tfb_tcp_output_wtime != NULL) {
error = (*tp->t_fb->tfb_tcp_output_wtime) (tp, &tv);
} else {
error = tp->t_fb->tfb_tcp_output(tp);
}
if (ninp && ninp->inp_ppcb) {
/*
* If we have a nxt inp, see if we can
* prefetch its ppcb. Note this may seem
* "risky" since we have no locks (other
* than the previous inp) and there no
* assurance that ninp was not pulled while
* we were processing inp and freed. If this
* occured it could mean that either:
*
* a) Its NULL (which is fine we won't go
* here) <or> b) Its valid (which is cool we
* will prefetch it) <or> c) The inp got
* freed back to the slab which was
* reallocated. Then the piece of memory was
* re-used and something else (not an
* address) is in inp_ppcb. If that occurs
* we don't crash, but take a TLB shootdown
* performance hit (same as if it was NULL
* and we tried to pre-fetch it).
*
* Considering that the likelyhood of <c> is
* quite rare we will take a risk on doing
* this. If performance drops after testing
* we can always take this out. NB: the
* kern_prefetch on amd64 actually has
* protection against a bad address now via
* the DMAP_() tests. This will prevent the
* TLB hit, and instead if <c> occurs just
* cause us to load cache with a useless
* address (to us).
*/
kern_prefetch(ninp->inp_ppcb, &prefetch_tp);
prefetch_tp = 1;
}
INP_WUNLOCK(inp);
INP_UNLOCK_ASSERT(inp);
CURVNET_RESTORE();
#ifdef INVARIANTS
if (mtx_owned(&hpts->p_mtx)) {
panic("Hpts:%p owns mtx prior-to lock line:%d",
hpts, __LINE__);
}
#endif
mtx_lock(&hpts->p_mtx);
if (logging_on)
tcp_hpts_log_it(hpts, hpts->p_inp, HPTSLOG_INP_DONE, 0, 4);
hpts->p_inp = NULL;
}
HPTS_MTX_ASSERT(hpts);
hpts->p_inp = NULL;
hpts->p_cur_slot++;
if (hpts->p_cur_slot >= NUM_OF_HPTSI_SLOTS) {
hpts->p_cur_slot = 0;
}
}
no_one:
HPTS_MTX_ASSERT(hpts);
hpts->p_prevtick = hpts->p_curtick;
hpts->p_delayed_by = 0;
/*
* Check to see if we took an excess amount of time and need to run
* more ticks (if we did not hit eno-bufs).
*/
/* Re-run any input that may be there */
(void)tcp_gethptstick(&tv);
if (!TAILQ_EMPTY(&hpts->p_input)) {
tcp_input_data(hpts, &tv);
}
#ifdef INVARIANTS
if (TAILQ_EMPTY(&hpts->p_input) &&
(hpts->p_on_inqueue_cnt != 0)) {
panic("tp:%p in_hpts input empty but cnt:%d",
hpts, hpts->p_on_inqueue_cnt);
}
#endif
tick_now = tcp_gethptstick(&tv);
if (SEQ_GT(tick_now, hpts->p_prevtick)) {
struct timeval res;
/* Did we really spend a full tick or more in here? */
timersub(&tv, ctick, &res);
if (res.tv_sec || (res.tv_usec >= HPTS_TICKS_PER_USEC)) {
counter_u64_add(hpts_loops, 1);
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_TOLONG, (uint32_t) res.tv_usec, tick_now);
}
*ctick = res;
hpts->p_curtick = tick_now;
goto again;
}
}
no_run:
{
uint32_t t = 0, i, fnd = 0;
if (hpts->p_on_queue_cnt) {
/*
* Find next slot that is occupied and use that to
* be the sleep time.
*/
for (i = 1, t = hpts->p_nxt_slot; i < NUM_OF_HPTSI_SLOTS; i++) {
if (TAILQ_EMPTY(&hpts->p_hptss[t]) == 0) {
fnd = 1;
break;
}
t = (t + 1) % NUM_OF_HPTSI_SLOTS;
}
if (fnd) {
hpts->p_hpts_sleep_time = i;
} else {
counter_u64_add(back_tosleep, 1);
#ifdef INVARIANTS
panic("Hpts:%p cnt:%d but non found", hpts, hpts->p_on_queue_cnt);
#endif
hpts->p_on_queue_cnt = 0;
goto non_found;
}
t++;
} else {
/* No one on the wheel sleep for all but 2 slots */
non_found:
if (hpts_sleep_max == 0)
hpts_sleep_max = 1;
hpts->p_hpts_sleep_time = min((NUM_OF_HPTSI_SLOTS - 2), hpts_sleep_max);
t = 0;
}
if (logging_on) {
tcp_hpts_log_it(hpts, inp, HPTSLOG_SLEEPSET, t, (hpts->p_hpts_sleep_time * HPTS_TICKS_PER_USEC));
}
}
}
void
__tcp_set_hpts(struct inpcb *inp, int32_t line)
{
struct tcp_hpts_entry *hpts;
INP_WLOCK_ASSERT(inp);
hpts = tcp_hpts_lock(inp);
if ((inp->inp_in_hpts == 0) &&
(inp->inp_hpts_cpu_set == 0)) {
inp->inp_hpts_cpu = hpts_cpuid(inp);
inp->inp_hpts_cpu_set = 1;
}
mtx_unlock(&hpts->p_mtx);
hpts = tcp_input_lock(inp);
if ((inp->inp_input_cpu_set == 0) &&
(inp->inp_in_input == 0)) {
inp->inp_input_cpu = hpts_cpuid(inp);
inp->inp_input_cpu_set = 1;
}
mtx_unlock(&hpts->p_mtx);
}
uint16_t
tcp_hpts_delayedby(struct inpcb *inp){
return (tcp_pace.rp_ent[inp->inp_hpts_cpu]->p_delayed_by);
}
static void
tcp_hpts_thread(void *ctx)
{
struct tcp_hpts_entry *hpts;
struct timeval tv;
sbintime_t sb;
hpts = (struct tcp_hpts_entry *)ctx;
mtx_lock(&hpts->p_mtx);
if (hpts->p_direct_wake) {
/* Signaled by input */
if (logging_on)
tcp_hpts_log_it(hpts, NULL, HPTSLOG_AWAKE, 1, 1);
callout_stop(&hpts->co);
} else {
/* Timed out */
if (callout_pending(&hpts->co) ||
!callout_active(&hpts->co)) {
if (logging_on)
tcp_hpts_log_it(hpts, NULL, HPTSLOG_AWAKE, 2, 2);
mtx_unlock(&hpts->p_mtx);
return;
}
callout_deactivate(&hpts->co);
if (logging_on)
tcp_hpts_log_it(hpts, NULL, HPTSLOG_AWAKE, 3, 3);
}
hpts->p_hpts_active = 1;
(void)tcp_gethptstick(&tv);
tcp_hptsi(hpts, &tv);
HPTS_MTX_ASSERT(hpts);
tv.tv_sec = 0;
tv.tv_usec = hpts->p_hpts_sleep_time * HPTS_TICKS_PER_USEC;
if (tcp_min_hptsi_time && (tv.tv_usec < tcp_min_hptsi_time)) {
tv.tv_usec = tcp_min_hptsi_time;
hpts->p_on_min_sleep = 1;
} else {
/* Clear the min sleep flag */
hpts->p_on_min_sleep = 0;
}
hpts->p_hpts_active = 0;
sb = tvtosbt(tv);
if (tcp_hpts_callout_skip_swi == 0) {
callout_reset_sbt_on(&hpts->co, sb, 0,
hpts_timeout_swi, hpts, hpts->p_cpu,
(C_DIRECT_EXEC | C_PREL(tcp_hpts_precision)));
} else {
callout_reset_sbt_on(&hpts->co, sb, 0,
hpts_timeout_dir, hpts,
hpts->p_cpu,
C_PREL(tcp_hpts_precision));
}
hpts->p_direct_wake = 0;
mtx_unlock(&hpts->p_mtx);
}
#undef timersub
static void
tcp_init_hptsi(void *st)
{
int32_t i, j, error, bound = 0, created = 0;
size_t sz, asz;
struct timeval tv;
sbintime_t sb;
struct tcp_hpts_entry *hpts;
char unit[16];
uint32_t ncpus = mp_ncpus ? mp_ncpus : MAXCPU;
tcp_pace.rp_proc = NULL;
tcp_pace.rp_num_hptss = ncpus;
hpts_loops = counter_u64_alloc(M_WAITOK);
back_tosleep = counter_u64_alloc(M_WAITOK);
sz = (tcp_pace.rp_num_hptss * sizeof(struct tcp_hpts_entry *));
tcp_pace.rp_ent = malloc(sz, M_TCPHPTS, M_WAITOK | M_ZERO);
asz = sizeof(struct hptsh) * NUM_OF_HPTSI_SLOTS;
for (i = 0; i < tcp_pace.rp_num_hptss; i++) {
tcp_pace.rp_ent[i] = malloc(sizeof(struct tcp_hpts_entry),
M_TCPHPTS, M_WAITOK | M_ZERO);
tcp_pace.rp_ent[i]->p_hptss = malloc(asz,
M_TCPHPTS, M_WAITOK);
hpts = tcp_pace.rp_ent[i];
/*
* Init all the hpts structures that are not specifically
* zero'd by the allocations. Also lets attach them to the
* appropriate sysctl block as well.
*/
mtx_init(&hpts->p_mtx, "tcp_hpts_lck",
"hpts", MTX_DEF | MTX_DUPOK);
TAILQ_INIT(&hpts->p_input);
for (j = 0; j < NUM_OF_HPTSI_SLOTS; j++) {
TAILQ_INIT(&hpts->p_hptss[j]);
}
sysctl_ctx_init(&hpts->hpts_ctx);
sprintf(unit, "%d", i);
hpts->hpts_root = SYSCTL_ADD_NODE(&hpts->hpts_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp_hpts),
OID_AUTO,
unit,
CTLFLAG_RW, 0,
"");
SYSCTL_ADD_INT(&hpts->hpts_ctx,
SYSCTL_CHILDREN(hpts->hpts_root),
OID_AUTO, "in_qcnt", CTLFLAG_RD,
&hpts->p_on_inqueue_cnt, 0,
"Count TCB's awaiting input processing");
SYSCTL_ADD_INT(&hpts->hpts_ctx,
SYSCTL_CHILDREN(hpts->hpts_root),
OID_AUTO, "out_qcnt", CTLFLAG_RD,
&hpts->p_on_queue_cnt, 0,
"Count TCB's awaiting output processing");
SYSCTL_ADD_UINT(&hpts->hpts_ctx,
SYSCTL_CHILDREN(hpts->hpts_root),
OID_AUTO, "active", CTLFLAG_RD,
&hpts->p_hpts_active, 0,
"Is the hpts active");
SYSCTL_ADD_UINT(&hpts->hpts_ctx,
SYSCTL_CHILDREN(hpts->hpts_root),
OID_AUTO, "curslot", CTLFLAG_RD,
&hpts->p_cur_slot, 0,
"What the current slot is if active");
SYSCTL_ADD_UINT(&hpts->hpts_ctx,
SYSCTL_CHILDREN(hpts->hpts_root),
OID_AUTO, "curtick", CTLFLAG_RD,
&hpts->p_curtick, 0,
"What the current tick on if active");
SYSCTL_ADD_UINT(&hpts->hpts_ctx,
SYSCTL_CHILDREN(hpts->hpts_root),
OID_AUTO, "logsize", CTLFLAG_RD,
&hpts->p_logsize, 0,
"Hpts logging buffer size");
hpts->p_hpts_sleep_time = NUM_OF_HPTSI_SLOTS - 2;
hpts->p_num = i;
hpts->p_prevtick = hpts->p_curtick = tcp_gethptstick(&tv);
hpts->p_prevtick -= 1;
hpts->p_prevtick %= NUM_OF_HPTSI_SLOTS;
hpts->p_cpu = 0xffff;
hpts->p_nxt_slot = 1;
hpts->p_logsize = tcp_hpts_logging_size;
if (hpts->p_logsize) {
sz = (sizeof(struct hpts_log) * hpts->p_logsize);
hpts->p_log = malloc(sz, M_TCPHPTS, M_WAITOK | M_ZERO);
}
callout_init(&hpts->co, 1);
}
/*
* Now lets start ithreads to handle the hptss.
*/
CPU_FOREACH(i) {
hpts = tcp_pace.rp_ent[i];
hpts->p_cpu = i;
error = swi_add(&hpts->ie, "hpts",
tcp_hpts_thread, (void *)hpts,
SWI_NET, INTR_MPSAFE, &hpts->ie_cookie);
if (error) {
panic("Can't add hpts:%p i:%d err:%d",
hpts, i, error);
}
created++;
if (tcp_bind_threads) {
if (intr_event_bind(hpts->ie, i) == 0)
bound++;
}
tv.tv_sec = 0;
tv.tv_usec = hpts->p_hpts_sleep_time * HPTS_TICKS_PER_USEC;
sb = tvtosbt(tv);
if (tcp_hpts_callout_skip_swi == 0) {
callout_reset_sbt_on(&hpts->co, sb, 0,
hpts_timeout_swi, hpts, hpts->p_cpu,
(C_DIRECT_EXEC | C_PREL(tcp_hpts_precision)));
} else {
callout_reset_sbt_on(&hpts->co, sb, 0,
hpts_timeout_dir, hpts,
hpts->p_cpu,
C_PREL(tcp_hpts_precision));
}
}
printf("TCP Hpts created %d swi interrupt thread and bound %d\n",
created, bound);
return;
}
SYSINIT(tcphptsi, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, tcp_init_hptsi, NULL);
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