19.03.2021 21:18, Minchan Kim пишет: >>> + if (ZERO_OR_NULL_PTR(cma_kobjs)) >>> + goto out; >>> + >>> + do { >>> + cma = &cma_areas[i]; >>> + cma->kobj = &cma_kobjs[i]; >> Does cma really need are pointer to cma_kobj? > Do you mean something like this? > > struct cma { > .. > .. > struct kobject *kobj; > }; > > Then, how could we we make kobject dynamic model? > > We need to get struct cma from kboj like below. > > static ssize_t alloc_pages_success_show(struct kobject *kobj, > struct kobj_attribute *attr, char *buf) > { > struct cma_kobject *cma_kobj = container_of(kobj, > struct cma_kobject, kobj); > struct cma *cma = cma_kobj->cma; > > return sysfs_emit(buf, "%llu\n", > atomic64_read(&cma->nr_pages_succeeded)); > } > > So kobj should be not a pointer in the container struct. > Am I missing your point? Otherwise, it would be great if you suggest > better idea. I meant that cma_kobj->cma is okay, but cma->kobj wasn't really used anywhere since struct cma can't be released. I.e. we could write kobject_put(&cma->kobj->kobj) as kobject_put(&cma_kobjs[i].kobj); But since we won't use the array anymore and maybe will get back to use the cma_stat, then it will be fine to add the pointer.