On Tue, 2015-07-14 at 14:43 +0300, Konstantin Khlebnikov wrote: > Kernel generates a lot of warnings when dst entry reference counter > overflows and becomes negative. This patch prints address of dst entry, > its refcount and then resets reference counter to INT_MAX/2. > > That bug was seen several times at machines with outdated 3.10.y kernels. > Most like it's already fixed in upstream. Anyway flood of that warnings > completely kills machine and makes further debugging impossible. > > Signed-off-by: Konstantin Khlebnikov <khlebni...@yandex-team.ru> > --- > net/core/dst.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/core/dst.c b/net/core/dst.c > index e956ce6d1378..2ed91082b3cf 100644 > --- a/net/core/dst.c > +++ b/net/core/dst.c > @@ -284,7 +284,8 @@ void dst_release(struct dst_entry *dst) > int newrefcnt; > > newrefcnt = atomic_dec_return(&dst->__refcnt); > - WARN_ON(newrefcnt < 0); > + if (WARN(newrefcnt < 0, "dst: %p refcnt: %d\n", dst, newrefcnt)) > + atomic_set(&dst->__refcnt, INT_MAX / 2); > if (unlikely(dst->flags & DST_NOCACHE) && !newrefcnt) > call_rcu(&dst->rcu_head, dst_destroy_rcu); > }
WARN_ON_ONCE() if you want, but setting __refcnt like this is absolutely a dirty hack. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
