avoid scoped_gc_epoch in kmalloc and a faster bucket() to speed up kmalloc/kmfree
avoid scoped_gc_epoch in kmalloc and a faster bucket() to speed up kmalloc/kmfree

bowlofstew/sv6,aclements/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6