On 10/12/2019 22:34, Vivien Didelot wrote: > On Tue, 10 Dec 2019 22:15:26 +0200, Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx> wrote: >>>>>> Why do you need percpu ? All of these seem to be incremented with the >>>>>> bridge lock held. A few more comments below. >>>>> >>>>> All other xstats are incremented percpu, I simply followed the pattern. >>>>> >>>> >>>> We have already a lock, we can use it and avoid the whole per-cpu memory handling. >>>> It seems to be acquired in all cases where these counters need to be changed. >>> >>> Since the other xstats counters are currently implemented this way, I prefer >>> to keep the code as is, until we eventually change them all if percpu is in >>> fact not needed anymore. >>> >>> The new series is ready and I can submit it now if there's no objection. >> >> There is a reason other counters use per-cpu - they're incremented without any locking from fast-path. >> The bridge STP code already has a lock which is acquired in all of these paths and we don't need >> this overhead and the per-cpu memory allocations. Unless you can find a STP codepath which actually >> needs per-cpu, I'd prefer you drop it. > > Ho ok I understand what you mean now. I'll drop the percpu attribute. > > > Thanks, > > Vivien > Great, thanks again. I think it's clear, but I'll add just in case to avoid extra work - you can drop the dynamic memory allocation altogether and make the struct part of net_bridge_port. Cheers, Nik
