On Tue, 11 Oct 2016 22:00:28 +0800 zijun_hu <zijun...@zoho.com> wrote:
> as shown by pcpu_build_alloc_info(), the number of units within a percpu > group is educed by rounding up the number of CPUs within the group to > @upa boundary, therefore, the number of CPUs isn't equal to the units's > if it isn't aligned to @upa normally. however, pcpu_page_first_chunk() > uses BUG_ON() to assert one number is equal the other roughly, so a panic > is maybe triggered by the BUG_ON() falsely. > > in order to fix this issue, the number of CPUs is rounded up then compared > with units's, the BUG_ON() is replaced by warning and returning error code > as well to keep system alive as much as possible. Under what circumstances is the triggered? In other words, what are the end-user visible effects of the fix? I mean, this is pretty old code (isn't it?) so what are you doing that triggers this?