On Thu, Oct 18, 2018 at 02:39:17PM +0100, Mel Gorman wrote: >On Thu, Oct 18, 2018 at 09:04:29PM +0800, Wei Yang wrote: >> This is not necessary to save the pfn to page->private. >> >> The pfn could be retrieved by page_to_pfn() directly. >> >> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> > >page_to_pfn is not free which is why it's cached. > Hi, Mel Thanks for your response. Not free means the access to mem_section? I have thought about the cache thing, so we assume the list is not that long, and the cache could hold those page->private for the whole loop? In my understand, it the cache has limited size, if more data accessed the cache will be overwritten. And another thing is: In case of CONFIG_SPARSEMEM_VMEMMAP, would this be a little different? Becase we get pfn by a simple addition. Which I think no need to cache it? Well, let me take a chance to say thanks to all, Mel, Michael and Matthew. Hope my silly question won't bother you too much. :-) >-- >Mel Gorman >SUSE Labs -- Wei Yang Help you, Help me
