On Wed, Jun 20, 2018 at 05:31:48PM +0200, Michal Hocko wrote:
> This?
> if (order > PAGE_ALLOC_COSTLY_ORDER)
> return OOM_SKIPPED;
>
> /*
> * We are in the middle of the charge context here, so we
> * don't want to block when potentially sitting on a callstack
> * that holds all kinds of filesystem and mm locks.
> *
> * cgroup1 allows disabling the OOM killer and waiting for outside
> * handling until the charge can succeed; remember the context and put
> * the task to sleep at the end of the page fault when all locks are
> * released.
> *
> * On the other hand, in-kernel OOM killer allows for an async victim
> * memory reclaim (oom_reaper) and that means that we are not solely
> * relying on the oom victim to make a forward progress and we can
> * invoke the oom killer here.
> *
> * Please note that mem_cgroup_oom_synchronize might fail to find a
> * victim and then we have rely on mem_cgroup_oom_synchronize otherwise
> * we would fall back to the global oom killer in pagefault_out_of_memory
> */
> if (memcg->oom_kill_disable) {
> if (!current->memcg_may_oom)
> return OOM_SKIPPED;
> css_get(&memcg->css);
> current->memcg_in_oom = memcg;
> current->memcg_oom_gfp_mask = mask;
> current->memcg_oom_order = order;
>
> return OOM_ASYNC;
> }
>
> if (mem_cgroup_out_of_memory(memcg, mask, order))
> return OOM_SUCCESS;
>
> WARN(!current->memcg_may_oom,
> "Memory cgroup charge failed because of no reclaimable memory! "
> "This looks like a misconfiguration or a kernel bug.");
> return OOM_FAILED;
Yep, this looks good IMO.
