This patch series removes the direct page pointer from struct page_cgroup, which saves 20% of per-page memcg memory overhead (Fedora and Ubuntu enable memcg per default, openSUSE apparently too). The node id or section number is encoded in the remaining free bits of pc->flags which allows calculating the corresponding page without the extra pointer. I ran, what I think is, a worst-case microbenchmark that just cats a large sparse file to /dev/null, because it means that walking the LRU list on behalf of per-cgroup reclaim and looking up pages from page_cgroups is happening constantly and at a high rate. But it made no measurable difference. A profile reported a 0.11% share of the new lookup_cgroup_page() function in this benchmark. Hannes -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>