2 * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
34 #include <sys/mutex.h>
36 #include <sys/sched.h>
38 #include <sys/sysctl.h>
41 #define IN_SUBR_COUNTER_C
42 #include <sys/counter.h>
45 counter_u64_zero(counter_u64_t c)
48 counter_u64_zero_inline(c);
52 counter_u64_fetch(counter_u64_t c)
55 return (counter_u64_fetch_inline(c));
59 counter_u64_alloc(int flags)
63 r = uma_zalloc(pcpu_zone_64, flags);
71 counter_u64_free(counter_u64_t c)
74 uma_zfree(pcpu_zone_64, c);
78 sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS)
83 out = counter_u64_fetch(*(counter_u64_t *)arg1);
85 error = SYSCTL_OUT(req, &out, sizeof(uint64_t));
87 if (error || !req->newptr)
91 * Any write attempt to a counter zeroes it.
93 counter_u64_zero(*(counter_u64_t *)arg1);
99 sysctl_handle_counter_u64_array(SYSCTL_HANDLER_ARGS)
104 out = malloc(arg2 * sizeof(uint64_t), M_TEMP, M_WAITOK);
105 for (int i = 0; i < arg2; i++)
106 out[i] = counter_u64_fetch(((counter_u64_t *)arg1)[i]);
108 error = SYSCTL_OUT(req, out, arg2 * sizeof(uint64_t));
111 if (error || !req->newptr)
115 * Any write attempt to a counter zeroes it.
117 for (int i = 0; i < arg2; i++)
118 counter_u64_zero(((counter_u64_t *)arg1)[i]);
124 * MP-friendly version of ppsratecheck().
126 * Returns non-negative if we are in the rate, negative otherwise.
127 * 0 - rate limit not reached.
128 * -1 - rate limit reached.
129 * >0 - rate limit was reached before, and was just reset. The return value
130 * is number of events since last reset.
133 counter_ratecheck(struct counter_rate *cr, int64_t limit)
141 if (now - cr->cr_ticks >= hz) {
143 * Time to clear the structure, we are in the next second.
144 * First try unlocked read, and then proceed with atomic.
146 if ((cr->cr_lock == 0) &&
147 atomic_cmpset_acq_int(&cr->cr_lock, 0, 1)) {
149 * Check if other thread has just went through the
150 * reset sequence before us.
152 if (now - cr->cr_ticks >= hz) {
153 val = counter_u64_fetch(cr->cr_rate);
154 counter_u64_zero(cr->cr_rate);
160 atomic_store_rel_int(&cr->cr_lock, 0);
163 * We failed to lock, in this case other thread may
164 * be running counter_u64_zero(), so it is not safe
165 * to do an update, we skip it.
170 counter_u64_add(cr->cr_rate, 1);
171 if (cr->cr_over != 0)
173 if (counter_u64_fetch(cr->cr_rate) > limit)
174 val = cr->cr_over = -1;