On 04/09/2018 07:10 AM, Jia-Ju Bai wrote: > dn_route_init() is never called in atomic context. > > The call chain ending up at dn_route_init() is: > [1] dn_route_init() <- decnet_init() > decnet_init() is only set as a parameter of module_init(). > > Despite never getting called from atomic context, > dn_route_init() calls __get_free_pages() with GFP_ATOMIC, > which waits busily for allocation. > GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, > to avoid busy waiting and improve the possibility of sucessful allocation. > > This is found by a static analysis tool named DCNS written by myself. > And I also manually check it. > > Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> > --- > net/decnet/dn_route.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c > index 0bd3afd..59ed12a 100644 > --- a/net/decnet/dn_route.c > +++ b/net/decnet/dn_route.c > @@ -1898,7 +1898,7 @@ void __init dn_route_init(void) > while(dn_rt_hash_mask & (dn_rt_hash_mask - 1)) > dn_rt_hash_mask--; > dn_rt_hash_table = (struct dn_rt_hash_bucket *) > - __get_free_pages(GFP_ATOMIC, order); > + __get_free_pages(GFP_KERNEL, order); > } while (dn_rt_hash_table == NULL && --order > 0); > > if (!dn_rt_hash_table) >
This might OOM under pressure. This would need __GFP_NOWARN | __GFP_NORETRY I guess, and would target net-next
