On 01.03.2016 12:16, Kirill Tkhai wrote: > On 29.02.2016 18:58, Vladimir Davydov wrote: >> An mm_struct may be pinned by a file. An example is vhost-net device >> created by a qemu/kvm (see vhost_net_ioctl -> vhost_net_set_owner -> >> vhost_dev_set_owner). If such process gets OOM-killed, the reference to >> its mm_struct will only be released from exit_task_work -> ____fput -> >> __fput -> vhost_net_release -> vhost_dev_cleanup, which is called after >> exit_mmap, where TIF_MEMDIE is cleared. As a result, we can start >> selecting the next victim before giving the last one a chance to free >> its memory. In practice, this leads to killing several VMs along with >> the fattest one. > > Do we have the same issue when group_leader's threads are owning the mm?
I.e. !group_leader, but threads in its group. >> https://jira.sw.ru/browse/PSBM-44683 >> >> Signed-off-by: Vladimir Davydov <[email protected]> >> --- >> kernel/exit.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/exit.c b/kernel/exit.c >> index 1cc765b48bd7..2715dc1dc0f5 100644 >> --- a/kernel/exit.c >> +++ b/kernel/exit.c >> @@ -520,8 +520,6 @@ static void exit_mm(struct task_struct * tsk) >> task_unlock(tsk); >> mm_update_next_owner(mm); >> mmput(mm); >> - if (test_thread_flag(TIF_MEMDIE)) >> - exit_oom_victim(); >> } >> >> /* >> @@ -819,6 +817,10 @@ void do_exit(long code) >> exit_fs(tsk); >> exit_task_namespaces(tsk); >> exit_task_work(tsk); >> + >> + if (test_thread_flag(TIF_MEMDIE)) >> + exit_oom_victim(); >> + >> check_stack_usage(); >> exit_thread(); >> >> _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
