Hi, While trying to fulfill's Christoph's request for using static_branches to do part of the role of number_of_cpusets in the cpuset cgroup, I took a much more extensive look at the cpuset code (Thanks Christoph). I started to feel that removing the cgroup_lock() from cpuset's destroy is not as safe as I first imagined. At the very best, is not safe enough to be bundled in a bugfix and deserves its own analysis. I started then to consider another approach. While I voiced many times that I would not like to do deferred updates for the static_branches, doing that during destroy time would be perfectly acceptable IMHO (creation is another story). In a summary, we are effectively calling the static_branch updates only when the last reference to the memcg is gone. And that is already asynchronous by nature, and we cope well with that. In memcg, it turns out that we already do deferred freeing of the memcg structure depending on the size of struct mem_cgroup. My proposal is to always do that, and then we get a worker more or less for free. Patch 2 is basically the same I had posted before, with minor adaptations, plus the addition of a commentary explaining a race as requested by Kame. Let me know if this is acceptable. Thanks Glauber Costa (2): Always free struct memcg through schedule_work() decrement static keys on real destroy time include/net/sock.h | 9 ++++++ mm/memcontrol.c | 54 ++++++++++++++++++++++++++-------- net/ipv4/tcp_memcontrol.c | 70 ++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 113 insertions(+), 20 deletions(-) -- 1.7.7.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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>