Could anyone can tell me why the operator in this code is '>=' ?

[mogu0401]

ngx_slab.c

void *
ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
{
    size_t            s;
    uintptr_t         p, n, m, mask, *bitmap;
    ngx_uint_t        i, slot, shift, map;
    ngx_slab_page_t  *page, *prev, *slots;

    if (size >= ngx_slab_max_size) {                // why not '>' ?

        ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
                       "slab alloc: %uz", size);

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,228488,228488#msg-228488