From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: Re: [PATCH net-next] bonding: make slave status notifications GFP_ATOMIC Date: Thu, 6 Mar 2014 10:02:06 +0800 Message-ID: <5317D71E.7080401@huawei.com> References: <1394025353-5496-1-git-send-email-vfalico@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Thomas Glanzmann , Jay Vosburgh , Andy Gospodarek To: Veaceslav Falico , Return-path: Received: from szxga02-in.huawei.com ([119.145.14.65]:3643 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755758AbaCFCCV (ORCPT ); Wed, 5 Mar 2014 21:02:21 -0500 In-Reply-To: <1394025353-5496-1-git-send-email-vfalico@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2014/3/5 21:15, Veaceslav Falico wrote: > Currently we're using GFP_KERNEL, however there are some path(s) where we > can hold some spinlocks, specifically bond->curr_slave_lock: > > [ 4.722916] BUG: sleeping function called from invalid context at mm/slub.c:965 > [ 4.724438] in_atomic(): 1, irqs_disabled(): 0, pid: 940, name: ifup-eth > [ 4.726034] 5 locks held by ifup-eth/940: > ...snip... > [ 4.734646] #4: (&bond->curr_slave_lock){+...+.}, at: [] bond_enslave+0xda6/0xdd0 [bonding] > ...snip... > [ 4.759081] [] bond_change_active_slave+0x191/0x3b0 [bonding] > [ 4.760917] [] bond_select_active_slave+0xf7/0x1d0 [bonding] > [ 4.762751] [] bond_enslave+0xdae/0xdd0 [bonding] > ...snip... > > As it's out of hot path and is a really rare event - change the gfp_t flags > to GFP_ATOMIC to avoid sleeping under spinlock. > > CC: Thomas Glanzmann > CC: Ding Tianhong > CC: Jay Vosburgh > CC: Andy Gospodarek > Signed-off-by: Veaceslav Falico > --- > drivers/net/bonding/bonding.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h > index 4303628..4cd451d 100644 > --- a/drivers/net/bonding/bonding.h > +++ b/drivers/net/bonding/bonding.h > @@ -292,7 +292,7 @@ static inline void bond_set_active_slave(struct slave *slave) > { > if (slave->backup) { > slave->backup = 0; > - rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_KERNEL); > + rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC); > } > } > > @@ -300,7 +300,7 @@ static inline void bond_set_backup_slave(struct slave *slave) > { > if (!slave->backup) { > slave->backup = 1; > - rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_KERNEL); > + rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC); > } > } > Acked-by: Ding Tianhong >