Re: [PATCH net-next] net: skbuff: Skip early return in skb_unref when debugging

From: Paolo Abeni
Date: Tue Jul 30 2024 - 07:16:16 EST




On 7/30/24 12:50, Florian Westphal wrote:
Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
else if (likely(!refcount_dec_and_test(&skb->users)))
return false;

I think one assumption behind CONFIG_DEBUG_NET is that enabling such config
should not have any measurable impact on performances.

If thats the case why does it exist at all?

I was under impression that entire reason for CONFIG_DEBUG_NET was
to enable more checks for fuzzers and the like, i.e. NOT for production
kernels.

I feel like I already had this discussion and I forgot the outcome, if so I'm sorry. To me the "but is safe to select." part in the knob description means this could be enabled in production, and AFAICS the CONFIG_DEBUG_NET-enabled code so far respects that assumption.

Thanks,

Paolo