On Thu, 6 Jan 2022 14:36:26 +0800 Menglong Dong wrote:
> Introduce the interface kfree_skb_reason(), which is able to pass
> the reason why the skb is dropped to 'kfree_skb' tracepoint.
> Add the 'reason' field to 'trace_kfree_skb', therefor user can get
> more detail information about abnormal skb with 'drop_monitor' or
> eBPF.
> All drop reasons are defined in the enum 'skb_drop_reason', and
> they will be print as string in 'kfree_skb' tracepoint in format
> of 'reason: XXX'.
> ( Maybe the reasons should be defined in a uapi header file, so that
> user space can use them? )
Since these drops are hardly hot path, why not simply use a string ?
An ENUM will not really help grep games.
tcp_drop(sk, skb, "csum error");
can refer to the previous discussion: https://lkml.org/lkml/2021/8/25/613