Function callout_callwheel_init

lib/ff_kern_timeout.c:224–263

* Kernel low level callwheel initialization * called on cpu0 during kernel startup. */

 * called on cpu0 during kernel startup.
 */
static void
callout_callwheel_init(void *dummy)
{
    struct callout_cpu *cc;

    /*
     * Calculate the size of the callout wheel and the preallocated
     * timeout() structures.
     * XXX: Clip callout to result of previous function of maxusers
     * maximum 384.  This is still huge, but acceptable.
     */
    memset(CC_CPU(0), 0, sizeof(cc_cpu));
    ncallout = imin(16 + maxproc + maxfiles, 18508);
    TUNABLE_INT_FETCH("kern.ncallout", &ncallout);

    /*
     * Calculate callout wheel size, should be next power of two higher
     * than 'ncallout'.
     */
    callwheelsize = 1 << fls(ncallout);
    callwheelmask = callwheelsize - 1;

    /*
     * Fetch whether we're pinning the swi's or not.
     */
    TUNABLE_INT_FETCH("kern.pin_default_swi", &pin_default_swi);
    TUNABLE_INT_FETCH("kern.pin_pcpu_swi", &pin_pcpu_swi);

    /*
     * Only cpu0 handles timeout(9) and receives a preallocation.
     *
     * XXX: Once all timeout(9) consumers are converted this can
     * be removed.
     */
    timeout_cpu = PCPU_GET(cpuid);
    cc = CC_CPU(timeout_cpu);
    cc->cc_callout = malloc(ncallout * sizeof(struct callout),
        M_CALLOUT, M_WAITOK);
    callout_cpu_init(cc, timeout_cpu);
}
SYSINIT(callwheel_init, SI_SUB_CPU, SI_ORDER_ANY, callout_callwheel_init, NULL);

/*