On Tue, 11 June 2013 17:16:01 -0400, Johannes Weiner wrote: > On Tue, Jun 11, 2013 at 02:29:21PM -0400, Jörn Engel wrote: > > I've seen a couple of instances where people try to impose a vsize > > limit simply because there is no rss limit in Linux. The vsize limit > > is a horrible approximation and even this patch seems to be an > > improvement. > > > > Would there be strong opposition to actually supporting RLIMIT_RSS? > > This is trivial to exploit by creating the mappings first and > populating them later, so while it may cover some use cases, it does > not have the protection against malicious programs aspect that all the > other rlimits have. Hm. The use case I have is that an application wants to limit itself. It is effectively a special assert to catch memory leaks and the like. So malicious programs are not my immediate concern. Of course the moment Linux supports RLIMIT_RSS people will use it to limit malicious programs, no matter how many scary warning we put in. > The right place to enforce the limit is at the point of memory > allocation, which raises the question what to do when the limit is > exceeded in a page fault. Reclaim from the process's memory? Kill > it? > > I guess the answer to these questions is "memory cgroups", so that's > why there is no real motivation to implement RLIMIT_RSS separately... Lack of opposition would be enough for me. But I guess we need a bit more for a mergeable patch than I did and I only did the existing patch because it seemed easy, not because it is important. Will keep the patch in my junk code folder for now. Jörn -- A surrounded army must be given a way out. -- Sun Tzu -- 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>