Re: [PATCH net-next v4 4/4] net: tun: track dropped skb via kfree_skb_reason()

[Jakub Kicinski]

On Tue, 1 Mar 2022 20:29:37 -0700 David Ahern wrote:
> On 3/1/22 7:50 PM, Jakub Kicinski wrote:
> > On Sat, 26 Feb 2022 00:49:29 -0800 Dongli Zhang wrote:  
> >> +	SKB_DROP_REASON_SKB_PULL,	/* failed to pull sk_buff data */
> >> +	SKB_DROP_REASON_SKB_TRIM,	/* failed to trim sk_buff data */  
> > 
> > IDK if these are not too low level and therefore lacking meaning.
> > 
> > What are your thoughts David?  
> 
> I agree. Not every kfree_skb is worthy of a reason. "Internal
> housekeeping" errors are random and nothing a user / admin can do about
> drops.
> 
> IMHO, the value of the reason code is when it aligns with SNMP counters
> (original motivation for this direction) and relevant details like TCP
> or UDP checksum mismatch, packets for a socket that is not open, socket
> is full, ring buffer is full, packets for "other host", etc.

Agreed :(