On Thu, 9 Jul 2015, Michal Hocko wrote: > > the titles were wrong for patches 2 and 3, but it doesn't mean we need to > > add hacks around the code before organizing this into struct oom_control > > It is much easier to backport _fixes_ into older kernels (and yes I do > care about that) if they do not depend on other cleanups. So I do not > understand your point here. Besides that the cleanup really didn't make > much change to the actuall fix because one way or another you still have > to add a simple condition to rule out a heuristic/configuration which > doesn't apply to sysrq+f path. > > So I am really lost in your argumentation here. > This isn't a bugfix: sysrq+f has, at least for eight years, been able to panic the kernel. We're not fixing a bug, we're changing behavior. It's quite appropriate to reorganize code before a behavior change to make it cleaner. > > or completely pointless comments and printks that will fill the kernel > > log. > > Could you explain what is so pointless about a comment which clarifies > the fact which is not obviously visible from the current function? > It states the obvious, a kthread is not going to be oom killed for oom_kill_allocating_task: it's not only current->mm, but also oom_unkillable_task(), which quite explicitly checks for PF_KTHREAD. I don't think any reader of this code will assume a kthread is going to be oom killed. > Also could you explain why the admin shouldn't get an information if > sysrq+f didn't kill anything because no eligible task has been found? The kernel log is the only notification mechanism that we have of the kernel killing a process, we want to avoid spamming it unnecessarily. The kernel log is not the appropriate place for your debugging information that would only specify that yes, out_of_memory() was called, but there was nothing actionable, especially when that trigger can be constantly invoked by userspace once panicking is no longer possible. -- 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>