There are a flurry of negatives among a no more than notional record profit for Commonwealth Bank for 2017. Bankwest's share of earnings for CBA have gone south, down ten per cent to A$702 million over the year to June.Carving off Bankwest's east coast business banking operation into the CBA group's business and private banking arm explains some of this fall. But the underlying fall in profit was seven per cent for Bankwest.In contrast, CBA's core retail banking operation produced a nine per cent rise in profit.CBA's aggregate risk weighted assets increased $0.6 billion or 0.1 per cent over the prior half to $437.1 billion.After allowing for an increase in risk weighted assets of $15 billion to meet APRA's requirements for Australian residential mortgages, CBA said "there was a decrease of $11.3 billion in RWA on the prior half."In part, this was due to a "reduction of exposure across corporate portfolios", driven by a sharper focus on returns.An addiction to discounting, mainly in the home loan market, proved an obstacle to any assumed margin benefit from extensive repricing on investor and interest-only loans.In guarded language, CBA summed up a three basis point decline in the net interest margin to 2.11 per cent as being due to "higher wholesale funding costs and increased competition in home and business lending, [that] more than offset asset repricing."