Re: [PATCH] net: optimize cmpxchg in ip_idents_reserve

From: Eric Dumazet
Date: Fri Jan 17 2020 - 11:35:16 EST




On 1/17/20 4:32 AM, Peter Zijlstra wrote:

>
> That's crazy, just accept that UBSAN is taking bonghits and ignore it.
> Use atomic_add_return() unconditionally.
>

Yes, we might simply add a comment so that people do not bug us if
their compiler is too old.

/* If UBSAN reports an error there, please make sure your compiler
* supports -fno-strict-overflow before reporting it.
*/
return atomic_add_return(segs + delta, p_id) - segs;