On Wed, Jun 06, 2018 at 08:55:15AM -0700, Nadav Amit wrote: > > -#define LATENCY_LIMIT (64 * PAGE_SIZE) > > +#define LATENCY_LIMIT (PMD_SIZE) > > > > unsigned long move_page_tables(struct vm_area_struct *vma, > > unsigned long old_addr, struct vm_area_struct *new_vma, > > This LATENCY_LIMIT is only used in move_page_tables() in the following > manner: > > next = (new_addr + PMD_SIZE) & PMD_MASK; > if (extent > next - new_addr) > extent = next - new_addr; > if (extent > LATENCY_LIMIT) > extent = LATENCY_LIMIT; > > If LATENCY_LIMIT is to be changed to PMD_SIZE, then IIUC the last condition > is not required, and LATENCY_LIMIT can just be removed (assuming there is no > underflow case that hides somewhere). > I see no problem removing it other than we may forget that we ever limited PTE lock hold times for any reason. I'm skeptical it will matter unless mremap-intensive workloads are a lot more common than I believe. -- Mel Gorman SUSE Labs
