On Thu, Sep 30, 2021 at 05:32:58PM +0100, Matthew Wilcox (Oracle) wrote: > Instead of calling put_page() one page at a time, pop pages off > the list if there are other refcounts and pass the remainder > to free_unref_page_list(). This should be a speed improvement, > but I have no measurements to support that. It's also not very > widely used today, so I can't say I've really tested it. I'm only > bothering with this patch because I'd like the IOMMU code to use it > https://lore.kernel.org/lkml/20210930162043.3111119-1-willy@xxxxxxxxxxxxx/ > > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> I see your motivation but you need to check that all users of put_pages_list (current and future) handle destroy_compound_page properly or handle it within put_pages_list. For example, the release_pages() user of free_unref_page_list calls __put_compound_page directly before freeing. put_pages_list as it stands will call dstroy_compound_page but free_unref_page_list does not destroy compound pages in free_pages_prepare -- Mel Gorman SUSE Labs
