subr_counter.c revision 253565
1/*- 2 * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/kern/subr_counter.c 253565 2013-07-23 11:16:40Z glebius $"); 29 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/kernel.h> 33#include <sys/lock.h> 34#include <sys/mutex.h> 35#include <sys/proc.h> 36#include <sys/sched.h> 37#include <sys/smp.h> 38#include <sys/sysctl.h> 39#include <vm/uma.h> 40 41#define IN_SUBR_COUNTER_C 42#include <sys/counter.h> 43 44static uma_zone_t uint64_pcpu_zone; 45 46void 47counter_u64_zero(counter_u64_t c) 48{ 49 50 counter_u64_zero_inline(c); 51} 52 53uint64_t 54counter_u64_fetch(counter_u64_t c) 55{ 56 57 return (counter_u64_fetch_inline(c)); 58} 59 60counter_u64_t 61counter_u64_alloc(int flags) 62{ 63 counter_u64_t r; 64 65 r = uma_zalloc(uint64_pcpu_zone, flags); 66 if (r != NULL) 67 counter_u64_zero(r); 68 69 return (r); 70} 71 72void 73counter_u64_free(counter_u64_t c) 74{ 75 76 uma_zfree(uint64_pcpu_zone, c); 77} 78 79int 80sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS) 81{ 82 uint64_t out; 83 int error; 84 85 out = counter_u64_fetch(*(counter_u64_t *)arg1); 86 87 error = SYSCTL_OUT(req, &out, sizeof(uint64_t)); 88 89 if (error || !req->newptr) 90 return (error); 91 92 /* 93 * Any write attempt to a counter zeroes it. 94 */ 95 counter_u64_zero(*(counter_u64_t *)arg1); 96 97 return (0); 98} 99 100static void 101counter_startup(void) 102{ 103 104 uint64_pcpu_zone = uma_zcreate("uint64 pcpu", sizeof(uint64_t), 105 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_PCPU); 106} 107SYSINIT(counter, SI_SUB_KMEM, SI_ORDER_ANY, counter_startup, NULL); 108