Re: [PATCH]snmp6 64-bit counter support in proc.c

["David S. Miller" <davem@xxxxxxxxxx>]

The most portable and simple algorithm to solve this on the reader
side is (and I recommend we don't special case this on 64-bit platforms
just to get wider testing):

        u32 high, low1, low2;

        do {
                low1 = stat & 0xffffffff;
                rmb();
                high = stat >> 32;
                rmb();
                low2 = stat & 0xffffffff;
        } while (low2 < low1);

Something like that.  The idea is to sample the lower 32-bit twice
and if it overflows resample both high and low halfs.