On Tue, Jul 9, 2019 at 1:35 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Tue, Jul 09, 2019 at 01:06:31AM +0800, Pengfei Li wrote: > > When unsigned long variables are subtracted from one another, > > the result is always non-negative. > > > > The vmap_area_list is sorted by address. > > > > So the following two conditions are always true. > > > > 1) if (busy->va_start - vmap_start > 0) > > 2) if (vmap_end - vmap_start > 0) > > > > Just remove them. > > That condition won't be true if busy->va_start == vmap_start. Yes, you're right. Sorry for my bad job.
