Messages in this thread | | | Date | Mon, 17 Sep 2018 22:05:44 -0700 (PDT) | From | Manish Kumar Singh <> | Subject | RE: [PATCH] bonding: avoid repeated display of same link status change |
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> -----Original Message----- > From: Eric Dumazet [mailto:eric.dumazet@gmail.com] > Sent: 17 सितम्बर 2018 20:08 > To: Manish Kumar Singh; netdev@vger.kernel.org > Cc: Jay Vosburgh; Veaceslav Falico; Andy Gospodarek; David S. Miller; linux- > kernel@vger.kernel.org > Subject: Re: [PATCH] bonding: avoid repeated display of same link status > change > > > > On 09/17/2018 12:20 AM, mk.singh@oracle.com wrote: > > From: Manish Kumar Singh <mk.singh@oracle.com> > > > > When link status change needs to be committed and rtnl lock couldn't be > > taken, avoid redisplay of same link status change message. > > > > Signed-off-by: Manish Kumar Singh <mk.singh@oracle.com> > > --- > > drivers/net/bonding/bond_main.c | 6 ++++-- > > include/net/bonding.h | 1 + > > 2 files changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/net/bonding/bond_main.c > b/drivers/net/bonding/bond_main.c > > index 217b790d22ed..fb4e3aff1677 100644 > > --- a/drivers/net/bonding/bond_main.c > > +++ b/drivers/net/bonding/bond_main.c > > @@ -2087,7 +2087,7 @@ static int bond_miimon_inspect(struct bonding > *bond) > > bond_propose_link_state(slave, BOND_LINK_FAIL); > > commit++; > > slave->delay = bond->params.downdelay; > > - if (slave->delay) { > > + if (slave->delay && !bond->rtnl_needed) { > > netdev_info(bond->dev, "link status down for > %sinterface %s, disabling it in %d ms\n", > > (BOND_MODE(bond) == > > BOND_MODE_ACTIVEBACKUP) ? > > @@ -2127,7 +2127,7 @@ static int bond_miimon_inspect(struct bonding > *bond) > > commit++; > > slave->delay = bond->params.updelay; > > > > - if (slave->delay) { > > + if (slave->delay && !bond->rtnl_needed) { > > netdev_info(bond->dev, "link status up for > interface %s, enabling it in %d ms\n", > > slave->dev->name, > > ignore_updelay ? 0 : > > @@ -2301,9 +2301,11 @@ static void bond_mii_monitor(struct > work_struct *work) > > if (!rtnl_trylock()) { > > delay = 1; > > should_notify_peers = false; > > + bond->rtnl_needed = true; > > How can you set a shared variable with no synchronization ? Thanks Eric for reviewing the patch. rtnl_needed is not a shared variable, it is part of bonding structure, that is one per bonding driver instance. There can't be two parallel instances of bond_miimon_inspect for a single bonding driver instance at any given point of time. and only bond_miimon_inspect updates it. That’s why I think there is no need of any synchronization here.
> > A bool is particularly dangerous here, at least on some arches. Thank you for cautioning us on bool usage. even a u8 can meet our requirement. we will change it. but; if time permits can you share more on "particularly dangerous here, at least on some arches".
F > > > goto re_arm; > > } > > > > + bond->rtnl_needed = false; > > bond_for_each_slave(bond, slave, iter) { > > bond_commit_link_state(slave, > BOND_SLAVE_NOTIFY_LATER); > > } > > diff --git a/include/net/bonding.h b/include/net/bonding.h > > index 808f1d167349..50d61cf77855 100644 > > --- a/include/net/bonding.h > > +++ b/include/net/bonding.h > > @@ -234,6 +234,7 @@ struct bonding { > > struct dentry *debug_dir; > > #endif /* CONFIG_DEBUG_FS */ > > struct rtnl_link_stats64 bond_stats; > > + bool rtnl_needed; > > }; > > > > #define bond_slave_get_rcu(dev) \ > >
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