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From: "lihuisong (C)" <lihuisong@huawei.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: dev@dpdk.org, thomas@monjalon.net, ferruh.yigit@amd.com,
	andrew.rybchenko@oktetlabs.ru, liuyonglong@huawei.com,
	"Morten Brørup" <mb@smartsharesystems.com>
Subject: Re: [PATCH v3 0/3] introduce maximum Rx buffer size
Date: Thu, 2 Nov 2023 09:59:01 +0800	[thread overview]
Message-ID: <177b8c04-a8f5-3889-dd26-474122b0be50@huawei.com> (raw)
In-Reply-To: <20231101090847.105f0fa1@fedora>


在 2023/11/2 0:08, Stephen Hemminger 写道:
> On Wed, 1 Nov 2023 10:36:07 +0800
> "lihuisong (C)" <lihuisong@huawei.com> wrote:
>
>>> Do we need to report this size? It's a common feature for all PMDs.
>>> It would make sense then to have max_rx_bufsize set to 16K by default
>>> in ethdev, and PMD could then raise/lower based on hardware.
>> It is not appropriate to set to 16K by default in ethdev layer.
>> Because I don't see any check for the upper bound in some driver, like
>> axgbe, enetc and so on.
>> I'm not sure if they have no upper bound.
>> And some driver's maximum buffer size is "16384(16K) - 128"
>> So it's better to set to UINT32_MAX by default.
>> what do you think?
> The goal is always giving application a working upper bound, and enforcing
> that as much as possible in ethdev layer. It doesnt matter which pattern
> does that.  Fortunately, telling application an incorrect answer is not fatal.
> If over estimated, application pool would be wasting space.
> If under estimated, application will get more fragmented packets.
I know what you mean.
If we set UINT32_MAX, it just means that driver don't report this upper 
bound.
This is also a very common way of handling. And it has no effect on the 
drivers that doesn't report this value.
On the contrary, if we set a default value (like 16K) in ethdev, user 
may be misunderstood and confused by that, right?
After all, this isn't the real upper bound of all drivers. And this 
fixed default value may affect the behavior of some driver that I didn't 
find their upper bound.
So I'd like to keep it as UINT32_MAX.
>
> .

  reply	other threads:[~2023-11-02  1:59 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-08  4:02 [RFC] ethdev: " Huisong Li
2023-08-11 12:07 ` Andrew Rybchenko
2023-08-15  8:16   ` lihuisong (C)
2023-08-15 11:10 ` [PATCH v1 0/3] " Huisong Li
2023-08-15 11:10   ` [PATCH v1 1/3] ethdev: " Huisong Li
2023-09-28 15:56     ` Ferruh Yigit
2023-10-24 12:21       ` lihuisong (C)
2023-08-15 11:10   ` [PATCH v1 2/3] app/testpmd: add maximum Rx buffer size display Huisong Li
2023-08-15 11:10   ` [PATCH v1 3/3] net/hns3: report maximum buffer size Huisong Li
2023-10-27  4:15 ` [PATCH v2 0/3] introduce maximum Rx " Huisong Li
2023-10-27  4:15   ` [PATCH v2 1/3] ethdev: " Huisong Li
2023-10-27  6:27     ` fengchengwen
2023-10-27  7:40     ` Morten Brørup
2023-10-28  1:23       ` lihuisong (C)
2023-10-27  4:15   ` [PATCH v2 2/3] app/testpmd: add maximum Rx buffer size display Huisong Li
2023-10-27  6:28     ` fengchengwen
2023-10-27  4:15   ` [PATCH v2 3/3] net/hns3: report maximum buffer size Huisong Li
2023-10-27  6:17     ` fengchengwen
2023-10-28  1:48 ` [PATCH v3 0/3] introduce maximum Rx " Huisong Li
2023-10-28  1:48   ` [PATCH v3 1/3] ethdev: " Huisong Li
2023-10-29 15:43     ` Stephen Hemminger
2023-10-30  3:08       ` lihuisong (C)
2023-10-28  1:48   ` [PATCH v3 2/3] app/testpmd: add maximum Rx buffer size display Huisong Li
2023-10-28  1:48   ` [PATCH v3 3/3] net/hns3: report maximum buffer size Huisong Li
2023-10-29 15:48   ` [PATCH v3 0/3] introduce maximum Rx " Stephen Hemminger
2023-10-30  1:25     ` lihuisong (C)
2023-10-30 18:48       ` Stephen Hemminger
2023-10-31  2:57         ` lihuisong (C)
2023-10-31  7:48           ` Morten Brørup
2023-10-31 15:40           ` Stephen Hemminger
2023-11-01  2:36             ` lihuisong (C)
2023-11-01 16:08               ` Stephen Hemminger
2023-11-02  1:59                 ` lihuisong (C) [this message]
2023-11-02 16:23                   ` Ferruh Yigit
2023-11-02 16:51                     ` Morten Brørup
2023-11-02 17:05                       ` Ferruh Yigit
2023-11-02 17:12                         ` Morten Brørup
2023-11-02 17:35                           ` Ferruh Yigit
2023-11-03  2:13                       ` lihuisong (C)
2023-11-02 12:16 ` [PATCH v4 " Huisong Li
2023-11-02 12:16   ` [PATCH v4 1/3] ethdev: " Huisong Li
2023-11-02 16:35     ` Ferruh Yigit
2023-11-03  2:21       ` lihuisong (C)
2023-11-03  3:30         ` Ferruh Yigit
2023-11-03  6:27           ` lihuisong (C)
2023-11-02 12:16   ` [PATCH v4 2/3] app/testpmd: add maximum Rx buffer size display Huisong Li
2023-11-02 16:42     ` Ferruh Yigit
2023-11-03  2:39       ` lihuisong (C)
2023-11-03  3:53         ` Ferruh Yigit
2023-11-03  6:37           ` lihuisong (C)
2023-11-02 12:16   ` [PATCH v4 3/3] net/hns3: report maximum buffer size Huisong Li
2023-11-03 10:27 ` [PATCH v5 0/3] introduce maximum Rx " Huisong Li
2023-11-03 10:27   ` [PATCH v5 1/3] ethdev: " Huisong Li
2023-11-03 12:37     ` Ivan Malov
2023-11-03 10:27   ` [PATCH v5 2/3] app/testpmd: add maximum Rx buffer size display Huisong Li
2023-11-03 10:27   ` [PATCH v5 3/3] net/hns3: report maximum buffer size Huisong Li
2023-11-03 11:53   ` [PATCH v5 0/3] introduce maximum Rx " Ferruh Yigit

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