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Message-ID: <6cebfd92-7ad0-496a-9f31-f4c696fb5cb8@linux.dev>
Date: Thu, 25 Apr 2024 16:50:43 -0700
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Subject: Re: [RFC PATCH bpf-next v5 1/2] net: Rename mono_delivery_time to
 tstamp_type for scalabilty
To: "Abhishek Chauhan (ABC)" <quic_abchauha@quicinc.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
 "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>,
 Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
 netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
 Andrew Halaney <ahalaney@redhat.com>,
 Martin KaFai Lau <martin.lau@kernel.org>,
 Daniel Borkmann <daniel@iogearbox.net>, bpf <bpf@vger.kernel.org>,
 kernel@quicinc.com
References: <20240424222028.1080134-1-quic_abchauha@quicinc.com>
 <20240424222028.1080134-2-quic_abchauha@quicinc.com>
 <662a69475869_1de39b29415@willemb.c.googlers.com.notmuch>
 <a84d314a-fca4-4317-9d33-0c7d3213c612@quicinc.com>
Content-Language: en-US
From: Martin KaFai Lau <martin.lau@linux.dev>
In-Reply-To: <a84d314a-fca4-4317-9d33-0c7d3213c612@quicinc.com>
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On 4/25/24 12:02 PM, Abhishek Chauhan (ABC) wrote:
>>>> @@ -9444,7 +9444,7 @@ static struct bpf_insn *bpf_convert_tstamp_read(const struct bpf_prog *prog,
>>>   					TC_AT_INGRESS_MASK | SKB_MONO_DELIVERY_TIME_MASK);
>>>   		*insn++ = BPF_JMP32_IMM(BPF_JNE, tmp_reg,
>>>   					TC_AT_INGRESS_MASK | SKB_MONO_DELIVERY_TIME_MASK, 2);
>>> -		/* skb->tc_at_ingress && skb->mono_delivery_time,
>>> +		/* skb->tc_at_ingress && skb->tstamp_type:1,
>> Is the :1 a stale comment after we discussed how to handle the 2-bit
> This is first patch which does not add tstamp_type:2 at the moment.
> This series is divided into two patches
> 1. One patchset => Just rename (So the comment is still skb->tstamp_type:1)
> 2. Second patchset => add another bit (comment is changed to skb->tstamp_type:2)

I would suggest to completely avoid the ":1" or ":2" part in patch 1. Just use 
"... && skb->tstamp_type". The number of bits does not matter. The tstamp_type 
will still be considered as a whole even if it would become 3 bits (unlikely) in 
the future.