On 2018-10-16 11:01:14 [-0700], Stephen Hemminger wrote: > On Tue, 16 Oct 2018 18:55:45 +0200 > Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > > > Also, ptr->var++ is not an atomic operation even on 64bit CPUs. Which > > means if try_fill_recv() runs on CPU0 (via virtnet_receive()) then the > > worker might run on CPU1. > > On modern CPU's increment of native types is atomic but not locked. > u64_stats_update_begin is a no-op on UP and also if BIT_PER_LONG != 32 On ARM64 you have load, inc, store. So if two CPUs increment the counter simultaneously we might lose one increment. That is why I asked if we care or not. Sebastian _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization