2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
36 #include <sys/mutex.h>
38 #include <sys/sched.h>
40 #include <sys/sysctl.h>
43 #define IN_SUBR_COUNTER_C
44 #include <sys/counter.h>
47 counter_u64_zero(counter_u64_t c)
50 counter_u64_zero_inline(c);
54 counter_u64_fetch(counter_u64_t c)
57 return (counter_u64_fetch_inline(c));
61 counter_u64_alloc(int flags)
64 return (uma_zalloc_pcpu(pcpu_zone_64, flags | M_ZERO));
68 counter_u64_free(counter_u64_t c)
71 uma_zfree_pcpu(pcpu_zone_64, c);
75 sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS)
80 out = counter_u64_fetch(*(counter_u64_t *)arg1);
82 error = SYSCTL_OUT(req, &out, sizeof(uint64_t));
84 if (error || !req->newptr)
88 * Any write attempt to a counter zeroes it.
90 counter_u64_zero(*(counter_u64_t *)arg1);
96 sysctl_handle_counter_u64_array(SYSCTL_HANDLER_ARGS)
101 out = malloc(arg2 * sizeof(uint64_t), M_TEMP, M_WAITOK);
102 for (int i = 0; i < arg2; i++)
103 out[i] = counter_u64_fetch(((counter_u64_t *)arg1)[i]);
105 error = SYSCTL_OUT(req, out, arg2 * sizeof(uint64_t));
108 if (error || !req->newptr)
112 * Any write attempt to a counter zeroes it.
114 for (int i = 0; i < arg2; i++)
115 counter_u64_zero(((counter_u64_t *)arg1)[i]);
121 * MP-friendly version of ppsratecheck().
123 * Returns non-negative if we are in the rate, negative otherwise.
124 * 0 - rate limit not reached.
125 * -1 - rate limit reached.
126 * >0 - rate limit was reached before, and was just reset. The return value
127 * is number of events since last reset.
130 counter_ratecheck(struct counter_rate *cr, int64_t limit)
138 if ((u_int)(now - cr->cr_ticks) >= hz) {
140 * Time to clear the structure, we are in the next second.
141 * First try unlocked read, and then proceed with atomic.
143 if ((cr->cr_lock == 0) &&
144 atomic_cmpset_acq_int(&cr->cr_lock, 0, 1)) {
146 * Check if other thread has just went through the
147 * reset sequence before us.
149 if ((u_int)(now - cr->cr_ticks) >= hz) {
150 val = counter_u64_fetch(cr->cr_rate);
151 counter_u64_zero(cr->cr_rate);
157 atomic_store_rel_int(&cr->cr_lock, 0);
160 * We failed to lock, in this case other thread may
161 * be running counter_u64_zero(), so it is not safe
162 * to do an update, we skip it.
167 counter_u64_add(cr->cr_rate, 1);
168 if (cr->cr_over != 0)
170 if (counter_u64_fetch(cr->cr_rate) > limit)
171 val = cr->cr_over = -1;