Re: [PATCH 6/8] mm: don't include <linux/memremap.h> in <linux/mm.h>

[Alistair Popple <apopple@nvidia.com>]

On Thursday, 10 February 2022 4:48:36 AM AEDT Christoph Hellwig wrote:
> On Mon, Feb 07, 2022 at 04:19:29PM -0500, Felix Kuehling wrote:
> >
> > Am 2022-02-07 um 01:32 schrieb Christoph Hellwig:
> >> Move the check for the actual pgmap types that need the free at refcount
> >> one behavior into the out of line helper, and thus avoid the need to
> >> pull memremap.h into mm.h.
> >>
> >> Signed-off-by: Christoph Hellwig <hch@lst.de>
> >
> > The amdkfd part looks good to me.
> >
> > It looks like this patch is not based on Alex Sierra's coherent memory 
> > series. He added two new helpers is_device_coherent_page and 
> > is_dev_private_or_coherent_page that would need to be moved along with 
> > is_device_private_page and is_pci_p2pdma_page.
> 
> FYI, here is a branch that contains a rebase of the coherent memory
> related patches on top of this series:
> 
> http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/pgmap-refcount
> 
> I don't have a good way to test this, but I'll at least let the build bot
> finish before sending it out (probably tomorrow).

Thanks, I ran up hmm-test which revealed a few minor problems with the rebase.
Fixes below.

---

diff --git a/mm/gup.c b/mm/gup.c
index cbb49abb7992..8e85c9fb8df4 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2007,7 +2007,6 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
 	if (!ret && list_empty(&movable_page_list) && !isolation_error_count)
 		return nr_pages;
 
-	ret = 0;
 unpin_pages:
 	for (i = 0; i < nr_pages; i++)
 		if (!pages[i])
diff --git a/mm/migrate.c b/mm/migrate.c
index f909f5a92757..1ae3e99baa50 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2686,12 +2686,11 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 			swp_entry = make_readable_device_private_entry(
 						page_to_pfn(page));
 		entry = swp_entry_to_pte(swp_entry);
-	} else {
-		if (is_zone_device_page(page) &&
-		    is_device_coherent_page(page)) {
+	} else if (is_zone_device_page(page) &&
+		    !is_device_coherent_page(page)) {
 			pr_warn_once("Unsupported ZONE_DEVICE page type.\n");
 			goto abort;
-		}
+	} else {
 		entry = mk_pte(page, vma->vm_page_prot);
 		if (vma->vm_flags & VM_WRITE)
 			entry = pte_mkwrite(pte_mkdirty(entry));