From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Dobriyan Subject: [PATCH 2/3] netns: add dummy struct inside "struct net_generic" Date: Fri, 2 Dec 2016 04:12:58 +0300 Message-ID: <20161202011258.GC31170@avx2> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, xemul@openvz.org To: davem@davemloft.net Return-path: Received: from mail-lf0-f66.google.com ([209.85.215.66]:35802 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757476AbcLAXNJ (ORCPT ); Thu, 1 Dec 2016 18:13:09 -0500 Received: by mail-lf0-f66.google.com with SMTP id p100so20469341lfg.2 for ; Thu, 01 Dec 2016 15:13:08 -0800 (PST) Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: This is precursor to fixing "[id - 1]" bloat inside net_generic(). Name "s" is chosen to complement name "u" often used for dummy unions. Signed-off-by: Alexey Dobriyan --- include/net/netns/generic.h | 6 ++++-- net/core/net_namespace.c | 8 ++++---- 2 files changed, 8 insertions(+), 6 deletions(-) --- a/include/net/netns/generic.h +++ b/include/net/netns/generic.h @@ -25,8 +25,10 @@ */ struct net_generic { - unsigned int len; - struct rcu_head rcu; + struct { + unsigned int len; + struct rcu_head rcu; + } s; void *ptr[0]; }; --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -50,7 +50,7 @@ static struct net_generic *net_alloc_generic(void) ng = kzalloc(generic_size, GFP_KERNEL); if (ng) - ng->len = max_gen_ptrs; + ng->s.len = max_gen_ptrs; return ng; } @@ -64,7 +64,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data) old_ng = rcu_dereference_protected(net->gen, lockdep_is_held(&net_mutex)); - if (old_ng->len >= id) { + if (old_ng->s.len >= id) { old_ng->ptr[id - 1] = data; return 0; } @@ -84,11 +84,11 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data) * the old copy for kfree after a grace period. */ - memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*)); + memcpy(&ng->ptr, &old_ng->ptr, old_ng->s.len * sizeof(void*)); ng->ptr[id - 1] = data; rcu_assign_pointer(net->gen, ng); - kfree_rcu(old_ng, rcu); + kfree_rcu(old_ng, s.rcu); return 0; }