FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_counter.c

     /*-
      * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
      * 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/10.0/sys/kern/subr_counter.c 253565 2013-07-23 11:16:40Z glebius $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/proc.h>
    #include <sys/sched.h>
    #include <sys/smp.h>
    #include <sys/sysctl.h>
    #include <vm/uma.h>
    
    #define IN_SUBR_COUNTER_C
    #include <sys/counter.h>
     
    static uma_zone_t uint64_pcpu_zone;
    
    void
    counter_u64_zero(counter_u64_t c)
    {
    
            counter_u64_zero_inline(c);
    }
    
    uint64_t
    counter_u64_fetch(counter_u64_t c)
    {
    
            return (counter_u64_fetch_inline(c));
    }
    
    counter_u64_t
    counter_u64_alloc(int flags)
    {
            counter_u64_t r;
    
            r = uma_zalloc(uint64_pcpu_zone, flags);
            if (r != NULL)
                    counter_u64_zero(r);
    
            return (r);
    }
    
    void
    counter_u64_free(counter_u64_t c)
    {
    
            uma_zfree(uint64_pcpu_zone, c);
    }
    
    int
    sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS)
    {
            uint64_t out;
            int error;
    
            out = counter_u64_fetch(*(counter_u64_t *)arg1);
    
            error = SYSCTL_OUT(req, &out, sizeof(uint64_t));
    
            if (error || !req->newptr)
                    return (error);
    
            /*
             * Any write attempt to a counter zeroes it.
             */
            counter_u64_zero(*(counter_u64_t *)arg1);
    
            return (0);
    }
    
   static void
   counter_startup(void)
   {
   
           uint64_pcpu_zone = uma_zcreate("uint64 pcpu", sizeof(uint64_t),
               NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_PCPU);
   }
   SYSINIT(counter, SI_SUB_KMEM, SI_ORDER_ANY, counter_startup, NULL);

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