On Wed, 12 Jun 2013, Michal Hocko wrote: > The patch is a big improvement with a minimum code overhead. Blocking > any task which sits on top of an unpredictable amount of locks is just > broken. So regardless how many users are affected we should merge it and > backport to stable trees. The problem is there since ever. We seem to > be surprisingly lucky to not hit this more often. > Right now it appears that that number of users is 0 and we're talking about a problem that was reported in 3.2 that was released a year and a half ago. The rules of inclusion in stable also prohibit such a change from being backported, specifically "It must fix a real bug that bothers people (not a, "This could be a problem..." type thing)". We have deployed memcg on a very large number of machines and I can run a query over all software watchdog timeouts that have occurred by deadlocking on i_mutex during memcg oom. It returns 0 results. > I am not quite sure I understand your reservation about the patch to be > honest. Andrew still hasn't merged this one although 1/2 is in. Perhaps he is as unconvinced? The patch adds 100 lines of code, including fields to task_struct for memcg, for a problem that nobody can reproduce. My question still stands: can anybody, even with an instrumented kernel to make it more probable, reproduce the issue this is addressing? -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>