From: Vlad Buslov <vladbu@mellanox•com>
To: Cong Wang <xiyou.wangcong@gmail•com>
Cc: Linux Kernel Network Developers <netdev@vger•kernel.org>,
Jamal Hadi Salim <jhs@mojatatu•com>,
Jiri Pirko <jiri@resnulli•us>, David Miller <davem@davemloft•net>
Subject: Re: [PATCH net-next 12/12] net: sched: flower: set unlocked flag for flower proto ops
Date: Tue, 19 Feb 2019 10:15:30 +0000 [thread overview]
Message-ID: <vbf5ztgqe2p.fsf@mellanox.com> (raw)
In-Reply-To: <CAM_iQpUkFG8C_sdQMDy_=zgMG-cAXeY8VyWescoGRO0PP9QzwQ@mail.gmail.com>
On Mon 18 Feb 2019 at 19:27, Cong Wang <xiyou.wangcong@gmail•com> wrote:
> On Wed, Feb 13, 2019 at 11:47 PM Vlad Buslov <vladbu@mellanox•com> wrote:
>>
>> Set TCF_PROTO_OPS_DOIT_UNLOCKED for flower classifier to indicate that its
>> ops callbacks don't require caller to hold rtnl lock.
>
> So, if this means RTNL is gone for all cls_flower changes, why
> do I still see rtnl_lock() in cls_flower.c after all your patches in
> this set?
It doesn't say that rtnl lock is gone, what it says is that caller
doesn't have to obtain rtnl lock before calling flower ops callbacks.
>
> For instance:
>
> 366 static void fl_destroy_filter_work(struct work_struct *work)
> 367 {
> 368 struct cls_fl_filter *f = container_of(to_rcu_work(work),
> 369 struct cls_fl_filter, rwork);
> 370
> 371 rtnl_lock();
> 372 __fl_destroy_filter(f);
> 373 rtnl_unlock();
> 374 }
This shouldn't be needed. Thanks for spotting it.
>
> and...
>
> 382 if (!rtnl_held)
> 383 rtnl_lock();
>
> ...
>
> 1436 if (!rtnl_held)
> 1437 rtnl_lock();
Drivers assume rtnl lock, so flower obtains it before calling offloads
API.
>
>
> Please explain in your changelog, otherwise it is very confusing.
Sorry for not making this stuff clear. I will expand cover letter with
more details.
>
> Thanks.
next prev parent reply other threads:[~2019-02-19 10:15 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-14 7:47 [PATCH net-next 00/12] Refactor flower classifier to remove dependency on rtnl lock Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 01/12] net: sched: flower: don't check for rtnl on head dereference Vlad Buslov
2019-02-18 19:08 ` Cong Wang
2019-02-19 9:45 ` Vlad Buslov
2019-02-20 22:33 ` Cong Wang
2019-02-21 17:45 ` Vlad Buslov
2019-02-22 19:32 ` Cong Wang
2019-02-25 16:11 ` Vlad Buslov
2019-02-25 22:39 ` Cong Wang
2019-02-26 14:57 ` Vlad Buslov
2019-02-28 0:49 ` Cong Wang
2019-02-28 18:35 ` Vlad Buslov
2019-03-02 0:51 ` Cong Wang
2019-02-14 7:47 ` [PATCH net-next 02/12] net: sched: flower: refactor fl_change Vlad Buslov
2019-02-14 20:34 ` Stefano Brivio
2019-02-15 10:38 ` Vlad Buslov
2019-02-15 10:47 ` Stefano Brivio
2019-02-15 16:25 ` Vlad Buslov
2019-02-18 18:20 ` Stefano Brivio
2019-02-14 7:47 ` [PATCH net-next 03/12] net: sched: flower: introduce reference counting for filters Vlad Buslov
2019-02-14 20:34 ` Stefano Brivio
2019-02-15 11:22 ` Vlad Buslov
2019-02-15 12:32 ` Stefano Brivio
2019-02-14 7:47 ` [PATCH net-next 04/12] net: sched: flower: track filter deletion with flag Vlad Buslov
2019-02-14 20:49 ` Stefano Brivio
2019-02-15 15:54 ` Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 05/12] net: sched: flower: add reference counter to flower mask Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 06/12] net: sched: flower: handle concurrent mask insertion Vlad Buslov
2019-02-15 22:46 ` Stefano Brivio
2019-02-14 7:47 ` [PATCH net-next 07/12] net: sched: flower: protect masks list with spinlock Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 08/12] net: sched: flower: handle concurrent filter insertion in fl_change Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 09/12] net: sched: flower: handle concurrent tcf proto deletion Vlad Buslov
2019-02-18 20:47 ` Cong Wang
2019-02-19 14:08 ` Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 10/12] net: sched: flower: protect flower classifier state with spinlock Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 11/12] net: sched: flower: track rtnl lock state Vlad Buslov
2019-02-15 22:46 ` Stefano Brivio
2019-02-18 9:35 ` Vlad Buslov
2019-02-14 7:47 ` [PATCH net-next 12/12] net: sched: flower: set unlocked flag for flower proto ops Vlad Buslov
2019-02-18 19:27 ` Cong Wang
2019-02-19 10:15 ` Vlad Buslov [this message]
2019-02-20 22:36 ` Cong Wang
2019-02-18 19:15 ` [PATCH net-next 00/12] Refactor flower classifier to remove dependency on rtnl lock Cong Wang
2019-02-19 10:00 ` Vlad Buslov
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