On Wed 20-01-21 15:54:04, Huang, Ying wrote: > Michal Hocko <mhocko@xxxxxxxx> writes: > > > On Wed 20-01-21 15:27:11, Huang Ying wrote: > >> To catch the error in updating the swap cache shadow entries or their count. > > > > What is the error? > > There's no error in the current code. But we will change the related > code in the future. So this checking will help us to prevent error in > the future. I will change the patch description to make it more clear. > > > Can it happens in the real life? Why do we need this > > patch? Is crashing the kernel the right way to handle the situation? > > Emm... The mistake to update swap shadow entries will hurt performance, > but will not trigger functionality bug. So it may be better to use > VM_WARN_ON_ONCE(). Yes a warning is much more appropriate approach. The question is whether a test like this is really necessary. But I will leave that to others to decide. It was really the bug on that hit my eyes. -- Michal Hocko SUSE Labs
