From: Vlad Buslov <vladbu@mellanox•com>
To: Jakub Kicinski <jakub.kicinski@netronome•com>,
"jiri@resnulli•us" <jiri@resnulli•us>
Cc: Vlad Buslov <vladbu@mellanox•com>,
"netdev@vger•kernel.org" <netdev@vger•kernel.org>,
"jhs@mojatatu•com" <jhs@mojatatu•com>,
"xiyou.wangcong@gmail•com" <xiyou.wangcong@gmail•com>,
"davem@davemloft•net" <davem@davemloft•net>
Subject: Re: [RFC PATCH net-next] net: sched: flower: refactor reoffload for concurrent access
Date: Wed, 17 Apr 2019 17:01:36 +0000 [thread overview]
Message-ID: <vbf8sw8h8k6.fsf@mellanox.com> (raw)
In-Reply-To: <20190417093432.495dcda6@cakuba.netronome.com>
On Wed 17 Apr 2019 at 19:34, Jakub Kicinski <jakub.kicinski@netronome•com> wrote:
> On Wed, 17 Apr 2019 07:29:36 +0000, Vlad Buslov wrote:
>> On Wed 17 Apr 2019 at 00:49, Jakub Kicinski <jakub.kicinski@netronome•com> wrote:
>> > On Tue, 16 Apr 2019 17:20:47 +0300, Vlad Buslov wrote:
>> >> @@ -1551,6 +1558,10 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
>> >> goto errout_mask;
>> >>
>> >> if (!tc_skip_hw(fnew->flags)) {
>> >> + spin_lock(&tp->lock);
>> >> + list_add(&fnew->hw_list, &head->hw_filters);
>> >> + spin_unlock(&tp->lock);
>> >> +
>> >> err = fl_hw_replace_filter(tp, fnew, rtnl_held, extack);
>> >> if (err)
>> >> goto errout_ht;
>> >
>> > Duplicated deletes should be fine, but I'm not sure same is true for
>> > adds. Won't seeing an add with the same cookie twice confuse drivers?
>> >
>> > There's also the minor issue of offloaded count being off in that
>> > case :)
>>
>> Hmmm, okay. Rejecting duplicate cookies should be a trivial change to
>> drivers though. Do you see any faults with this approach in general?
>
> Trivial or not it adds up, the stack should make driver authors' job as
> easy as possible. The simplest thing to do would be to add a mutex
Agree. However, all driver flower offload implementations already have
all necessary functionality to lookup flow by cookie because they need
it to implement flow deletion.
> around the HW calls. But that obviously doesn't work for you, cause
> you want multiple outstanding requests to the FW for a single tp,
> right?
Right.
>
> How about a RW lock, that would take R on normal add/replace/del paths
> and W on replays? That should scale, no?
Yes. But I would prefer to avoid adding another sleeping lock on
rule update path of every filter (including non-offloaded use cases when
reoffload is not used at all).
Jiri, what approach would you prefer?
next prev parent reply other threads:[~2019-04-17 17:01 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-05 17:56 [PATCH net-next] net: sched: flower: insert filter to ht before offloading it to hw Vlad Buslov
2019-04-06 5:59 ` Jiri Pirko
2019-04-08 2:34 ` David Miller
2019-04-08 22:26 ` Jakub Kicinski
2019-04-09 8:23 ` Vlad Buslov
2019-04-09 17:10 ` Jakub Kicinski
2019-04-10 14:53 ` Vlad Buslov
2019-04-10 15:48 ` Jakub Kicinski
2019-04-10 16:02 ` Vlad Buslov
2019-04-10 16:09 ` Jakub Kicinski
2019-04-10 16:26 ` Vlad Buslov
2019-04-10 17:00 ` Jakub Kicinski
2019-04-16 14:20 ` [RFC PATCH net-next] net: sched: flower: refactor reoffload for concurrent access Vlad Buslov
2019-04-16 21:49 ` Jakub Kicinski
2019-04-17 7:29 ` Vlad Buslov
2019-04-17 16:34 ` Jakub Kicinski
2019-04-17 17:01 ` Vlad Buslov [this message]
2019-04-18 16:33 ` Vlad Buslov
2019-04-18 17:46 ` Jakub Kicinski
2019-04-18 17:58 ` Vlad Buslov
2019-04-18 18:02 ` Jakub Kicinski
2019-04-18 18:13 ` Vlad Buslov
2019-04-18 18:15 ` Jakub Kicinski
2019-04-11 11:13 ` [PATCH net-next] net: sched: flower: insert filter to ht before offloading it to hw Ido Schimmel
2019-04-11 11:28 ` Vlad Buslov
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