For admission committees, how important are the (upward) trends in your GPA and how much will it remedy lackluster performance in the past?
Background: I'm an international CS applicant with an overall undergraduate GPA of around 2.8 with a GPA of 3.5 in the last two years (undergrad took 5 years total). I'm also finishing my masters with a 4.0 GPA. Considering these facts, how much should I expect my overall undergraduate GPA to hurt my chances for Ph.D. admission in the US/Canada?
(I'm aware of other factors such as recommendations, GRE and research experience. However, I would like to keep this question specific to the effect of positive GPA trends vs. overall GPA)
P.S: I have looked at seemingly similar questions/answers on the site but none of them cover this specific question.