# Re: \[PATCH v2 1/7\] Basic kernel memory functionality for the Memory Controller - From: Glauber Costa \ - Date: 2011-09-18 19:12:10 - List: netdev - Page: https://ratatoskr.run/netdev/2011/09/3764731 - Thread: https://ratatoskr.run/netdev/2011/09/3763743/t.md ```text On 09/18/2011 04:05 PM, Kirill A. Shutemov wrote: > On Sun, Sep 18, 2011 at 12:39:12AM -0300, Glauber Costa wrote: >>> No kernel memory accounting for root cgroup, right? >> Not sure. Maybe kernel memory accounting is useful even for root cgroup. >> Same as normal memory accounting... what we want to avoid is kernel >> memory limits. OTOH, if we are not limiting it anyway, accounting it is >> just useless overhead... Even the statistics can then be gathered >> through all >> the proc files that show slab usage, I guess? > > It's better to leave root cgroup without accounting. At least for now. > We can add it later if needed. Fair. >>> >>>> @@ -3979,6 +3999,10 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) >>>> else >>>> val = res_counter_read_u64(&mem->memsw, name); >>>> break; >>>> + case _KMEM: >>>> + val = res_counter_read_u64(&mem->kmem, name); >>>> + break; >>>> + >>> >>> Always zero in root cgroup? >> >> Yes, if we're not accounting, it should be zero. WARN_ON, maybe? > > -ENOSYS? > I'd personally prefer WARN_ON. It is good symmetry from userspace PoV to always be able to get a value out of it. Also, it something goes wrong and it is not zero for some reason, this will help us find it. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org ```