Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when allocate a odd alignment area

From: Michal Hocko
Date: Tue Oct 11 2016 - 13:22:37 EST

On Tue 11-10-16 21:24:50, zijun_hu wrote:
> From: zijun_hu <zijun_hu@xxxxxxx>
> the LSB of a chunk->map element is used for free/in-use flag of a area
> and the other bits for offset, the sufficient and necessary condition of
> this usage is that both size and alignment of a area must be even numbers
> however, pcpu_alloc() doesn't force its @align parameter a even number
> explicitly, so a odd @align maybe causes a series of errors, see below
> example for concrete descriptions.

Is or was there any user who would use a different than even (or power of 2)
alighment? If not is this really worth handling?

Michal Hocko