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? > 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
