Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH 3/9] oom: oom_kill_process() doesn't select kthread child | Date | Thu, 17 Jun 2010 10:51:33 +0900 (JST) |
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> On Wed, Jun 16, 2010 at 08:32:08PM +0900, KOSAKI Motohiro wrote: > > Now, select_bad_process() have PF_KTHREAD check, but oom_kill_process > > doesn't. It mean oom_kill_process() may choose wrong task, especially, > > when the child are using use_mm(). > Now oom_kill_process is called by three place. > > 1. mem_cgroup_out_of_memory > 2. out_of_memory with sysctl_oom_kill_allocating_task > 3. out_of_memory with non-sysctl_oom_kill_allocating_task > > I think it's no problem in 1 and 3 since select_bad_process already checks > PF_KTHREAD. The problem in in 2. > So How about put the check before calling oom_kill_process in case of > sysctl_oom_kill_allocating task? > > if (sysctl_oom_kill_allocating_task) { > if (!current->flags & PF_KTHREAD) > oom_kill_process(); > > It can remove duplicated PF_KTHREAD check in select_bad_process and > oom_kill_process.
This patch changed child selection logic. select_bad_process() doesn't check victim's child. IOW, this is necessary when all 1-3.
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