On Tue, Mar 30, 2021 at 06:15:19PM +0800, Muchun Song wrote: > All the callers of mem_cgroup_page_lruvec() just pass page_pgdat(page) > as the 2nd parameter to it (except isolate_migratepages_block()). But > for isolate_migratepages_block(), the page_pgdat(page) is also equal > to the local variable of @pgdat. So mem_cgroup_page_lruvec() do not > need the pgdat parameter. Just remove it to simplify the code. > > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> There is a minor benefit in not doing the page_pgdat() lookup twice. But I think it only really matters on 32-bit NUMA, where we have more than one node but not enough space in page->flags to store the nid, and so page_to_nid() is out-of-line and needs to go through section. Those setups aren't really around anymore, and certainly don't justify the hassle (and potential bugs) of the awkward interface. Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
