On Tue, Mar 23, 2021 at 12:50:50PM -0700, Minchan Kim wrote: > + /* the number of CMA page successful allocations */ > + atomic64_t nr_pages_succeeded; > +void cma_sysfs_alloc_pages_count(struct cma *cma, size_t count) > +{ > + atomic64_add(count, &cma->nr_pages_succeeded); > +} I don't understand. A size_t is a byte count. But the variable is called 'nr_pages'. So which is it, a byte count or a page count? > +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)); ... if it's in bytes, it should probably be reported in kilobytes and be suffixed with a 'K' like many other stats.