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From: Kui-Feng Lee <sinquersw@gmail.com>
To: Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <martin.lau@linux.dev>
Cc: netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
	Kui-Feng Lee <kuifeng@meta.com>,
	bpf@vger.kernel.org, ast@kernel.org, song@kernel.org,
	kernel-team@meta.com, andrii@kernel.org, sdf@google.com
Subject: Re: [PATCH bpf-next v7 2/8] net: Update an existing TCP congestion control algorithm.
Date: Fri, 17 Mar 2023 14:46:34 -0700	[thread overview]
Message-ID: <8a268c26-ea57-89ec-9fea-72ec5b8e12e2@gmail.com> (raw)
In-Reply-To: <b8b54ef5-8a24-5886-8f4e-8856dbaa9c34@iogearbox.net>



On 3/17/23 10:23, Daniel Borkmann wrote:
> On 3/17/23 6:18 PM, Martin KaFai Lau wrote:
>> On 3/17/23 8:23 AM, Daniel Borkmann wrote:
>>>  From the function itself what is not clear whether
>>> callers that replace an existing one should do the synchronize_rcu() 
>>> themselves or if this should
>>> be part of tcp_update_congestion_control?
>>
>> bpf_struct_ops_map_free (in patch 1) also does synchronize_rcu() for 
>> another reason (bpf_setsockopt), so the caller (bpf_struct_ops) is 
>> doing it. From looking at tcp_unregister_congestion_control(), make 
>> sense that it is more correct to have another synchronize_rcu() also 
>> in tcp_update_congestion_control in case there will be other non 
>> bpf_struct_ops caller doing update in the future.
> 
> Agree, I was looking at 'bpf: Update the struct_ops of a bpf_link', and 
> essentially as-is
> it was implicit via map free. +1, tcp_update_congestion_control() would 
> be more obvious and
> better for other/non-BPF users.

It makes sense to me.
I will refactor functions as well.

> 
> Thanks,
> Daniel

  reply	other threads:[~2023-03-17 21:48 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-16  2:36 [PATCH bpf-next v7 0/8] Transit between BPF TCP congestion controls Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 1/8] bpf: Retire the struct_ops map kvalue->refcnt Kui-Feng Lee
2023-03-17 16:47   ` Martin KaFai Lau
2023-03-17 20:41     ` Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 2/8] net: Update an existing TCP congestion control algorithm Kui-Feng Lee
2023-03-17 15:23   ` Daniel Borkmann
2023-03-17 17:18     ` Martin KaFai Lau
2023-03-17 17:23       ` Daniel Borkmann
2023-03-17 21:46         ` Kui-Feng Lee [this message]
2023-03-17 23:07     ` Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 3/8] bpf: Create links for BPF struct_ops maps Kui-Feng Lee
2023-03-17 18:10   ` Martin KaFai Lau
2023-03-17 20:52     ` Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 4/8] libbpf: Create a bpf_link in bpf_map__attach_struct_ops() Kui-Feng Lee
2023-03-17 18:44   ` Martin KaFai Lau
2023-03-17 21:00     ` Kui-Feng Lee
2023-03-17 22:23   ` Andrii Nakryiko
2023-03-17 23:48     ` Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 5/8] bpf: Update the struct_ops of a bpf_link Kui-Feng Lee
2023-03-17 19:23   ` Martin KaFai Lau
2023-03-17 21:39     ` Kui-Feng Lee
2023-03-18  1:11     ` Kui-Feng Lee
2023-03-18  5:38       ` Martin KaFai Lau
2023-03-17 22:27   ` Andrii Nakryiko
2023-03-18  0:41     ` Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 6/8] libbpf: Update a bpf_link with another struct_ops Kui-Feng Lee
2023-03-17 19:42   ` Martin KaFai Lau
2023-03-17 21:40     ` Kui-Feng Lee
2023-03-17 22:33   ` Andrii Nakryiko
2023-03-18  1:17     ` Kui-Feng Lee
2023-03-16  2:36 ` [PATCH bpf-next v7 7/8] libbpf: Use .struct_ops.link section to indicate a struct_ops with a link Kui-Feng Lee
2023-03-17 22:35   ` Andrii Nakryiko
2023-03-16  2:36 ` [PATCH bpf-next v7 8/8] selftests/bpf: Test switching TCP Congestion Control algorithms Kui-Feng Lee

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