From: Taehee Yoo <ap420073@gmail.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: "David Miller" <davem@davemloft.net>,
Netdev <netdev@vger.kernel.org>,
linux-wireless@vger.kernel.org,
"Jakub Kicinski" <jakub.kicinski@netronome.com>,
j.vosburgh@gmail.com, vfalico@gmail.com,
"Andy Gospodarek" <andy@greyhouse.net>,
"Jiří Pírko" <jiri@resnulli.us>,
"Sabrina Dubroca" <sd@queasysnail.net>,
"Roopa Prabhu" <roopa@cumulusnetworks.com>,
saeedm@mellanox.com, manishc@marvell.com, rahulv@marvell.com,
kys@microsoft.com, haiyangz@microsoft.com,
"Stephen Hemminger" <stephen@networkplumber.org>,
sashal@kernel.org, hare@suse.de, varun@chelsio.com,
ubraun@linux.ibm.com, kgraul@linux.ibm.com,
"Jay Vosburgh" <jay.vosburgh@canonical.com>,
"Cody Schuffelen" <schuffelen@google.com>,
bjorn@mork.no
Subject: Re: [PATCH net v4 07/12] macvlan: use dynamic lockdep key instead of subclass
Date: Tue, 8 Oct 2019 17:13:22 +0900 [thread overview]
Message-ID: <CAMArcTVvpUsz013K6UXpbKiKfpMKaTsGmJhnv3YfiGOLnh4Zig@mail.gmail.com> (raw)
In-Reply-To: <bb48fca5a5ffb0a877b2bff8de07ec8090b63427.camel@sipsolutions.net>
On Mon, 7 Oct 2019 at 20:41, Johannes Berg <johannes@sipsolutions.net> wrote:
>
Hi Johannes,
> On Sat, 2019-10-05 at 18:13 +0900, Taehee Yoo wrote:
> >
> > If we place lockdep keys into "struct net_device", this macro would be a
> > little bit modified and reused. And driver code shape will not be huge
> > changed. I think this way is better than this v4 way.
> > So I will try it.
>
> What I was thinking was that if we can do this for every VLAN netdev,
> why shouldn't we do it for *every* netdev unconditionally? Some code
> could perhaps even be simplified if this was just a general part of
> netdev allocation.
>
Your opinion makes sense.
I think there is no critical reason that every netdev shouldn't have
own lockdep keys. By comparison, the benefits are obvious.
> > > But it seems to me the whole nesting also has to be applied here?
> > >
> > > __dev_xmit_skb:
> > > * qdisc_run_begin()
> > > * sch_direct_xmit()
> > > * HARD_TX_LOCK(dev, txq, smp_processor_id());
> > > * dev_hard_start_xmit() // say this is VLAN
> > > * dev_queue_xmit() // on real_dev
> > > * __dev_xmit_skb // recursion on another netdev
> > >
> > > Now if you have VLAN-in-VLAN the whole thing will recurse right?
> > >
> >
> > I have checked on this routine.
> > Only xmit_lock(HARD_TX_LOCK) could be nested. other
> > qdisc locks(runinng, busylock) will not be nested.
>
> OK, I still didn't check it too closely I guess, or got confused which
> lock I should look at.
>
> > This patch already
> > handles the _xmit_lock key. so I think there is no problem.
>
> Right
>
> > But I would like to place four lockdep keys(busylock, address,
> > running, _xmit_lock) into "struct net_device" because of code complexity.
> >
> > Let me know if I misunderstood anything.
>
> Nothing to misunderstand - I was just asking/wondering why the qdisc
> locks were not treated the same way.
>
I'm always thankful for your detailed and careful reviews.
> johannes
>
Thank you,
Taehee Yoo
next prev parent reply other threads:[~2019-10-08 8:13 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-28 16:48 [PATCH net v4 00/12] net: fix nested device bugs Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 01/12] net: core: limit nested device depth Taehee Yoo
2019-09-28 19:36 ` Johannes Berg
2019-09-29 11:05 ` Taehee Yoo
2019-10-01 7:11 ` Johannes Berg
2019-10-01 13:53 ` Taehee Yoo
2019-10-01 13:57 ` Johannes Berg
2019-10-01 18:23 ` Taehee Yoo
2019-10-10 10:19 ` Sabrina Dubroca
2019-10-12 11:42 ` Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 02/12] vlan: use dynamic lockdep key instead of subclass Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 03/12] bonding: fix unexpected IFF_BONDING bit unset Taehee Yoo
2019-09-30 20:48 ` Jay Vosburgh
2019-09-28 16:48 ` [PATCH net v4 04/12] bonding: use dynamic lockdep key instead of subclass Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 05/12] team: use dynamic lockdep key instead of static key Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 06/12] macsec: use dynamic lockdep key instead of subclass Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 07/12] macvlan: " Taehee Yoo
2019-09-28 19:14 ` Johannes Berg
2019-09-29 8:03 ` Taehee Yoo
2019-10-01 7:25 ` Johannes Berg
2019-10-05 9:13 ` Taehee Yoo
2019-10-07 11:41 ` Johannes Berg
2019-10-08 8:13 ` Taehee Yoo [this message]
2019-10-21 16:00 ` Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 08/12] macsec: fix refcnt leak in module exit routine Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 09/12] net: core: add ignore flag to netdev_adjacent structure Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 10/12] vxlan: add adjacent link to limit depth level Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 11/12] net: remove unnecessary variables and callback Taehee Yoo
2019-09-28 19:42 ` Johannes Berg
2019-09-28 16:48 ` [PATCH net v4 12/12] virt_wifi: fix refcnt leak in module exit routine Taehee Yoo
2019-09-28 18:57 ` Johannes Berg
2019-10-07 11:22 ` Sabrina Dubroca
2019-10-08 6:53 ` Taehee Yoo
2019-09-28 19:20 ` [PATCH net v4 00/12] net: fix nested device bugs Johannes Berg
2019-09-29 8:31 ` Taehee Yoo
2019-10-01 7:39 ` Johannes Berg
2019-10-05 9:40 ` Taehee Yoo
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