diff mbox series

[09/12] mm: add page_rmappable_folio() wrapper

Message ID f4dc7bb6-be3a-c1b-c30-37c4e0c16e4d@google.com (mailing list archive)
State New
Headers show
Series mempolicy: cleanups leading to NUMA mpol without vma | expand

Commit Message

Hugh Dickins Sept. 25, 2023, 8:32 a.m. UTC
folio_prep_large_rmappable() is being used repeatedly along with a
conversion from page to folio, a check non-NULL, a check order > 1:
wrap it all up into struct folio *page_rmappable_folio(struct page *).

Signed-off-by: Hugh Dickins <hughd@google.com>
---
 include/linux/huge_mm.h | 13 +++++++++++++
 mm/mempolicy.c          | 17 +++--------------
 mm/page_alloc.c         |  8 ++------
 3 files changed, 18 insertions(+), 20 deletions(-)

Comments

Matthew Wilcox (Oracle) Sept. 25, 2023, 10:58 p.m. UTC | #1
On Mon, Sep 25, 2023 at 01:32:02AM -0700, Hugh Dickins wrote:
>  {
>  	struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
> -			preferred_nid, nodemask);
> +					  preferred_nid, nodemask);

I really prefer not to do this "align arguments with opening bracket"
style.  As long as they're indented enough to make them visually distinct
from indentation-for-if-blocks, I find it annoying when functions get
renamed to something with a different length and somebody then wastes
time reindenting all the arguments to match.

> +	return page_rmappable_folio(page);

I don't particularly object to the main thrust of this patch.  I'm not
sure I like it in huge_mm.h though.  Maybe in mm/internal.h?  I
wouldn't want anyone outside mm/ calling it.
Hugh Dickins Sept. 26, 2023, 9:58 p.m. UTC | #2
On Mon, 25 Sep 2023, Matthew Wilcox wrote:
> On Mon, Sep 25, 2023 at 01:32:02AM -0700, Hugh Dickins wrote:
> >  {
> >  	struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
> > -			preferred_nid, nodemask);
> > +					  preferred_nid, nodemask);
> 
> I really prefer not to do this "align arguments with opening bracket"
> style.  As long as they're indented enough to make them visually distinct
> from indentation-for-if-blocks, I find it annoying when functions get
> renamed to something with a different length and somebody then wastes
> time reindenting all the arguments to match.

Okay, I don't care much about inserting spaces to align with the bracket,
but didn't like those continuation args leftward of function name above.
I'll adjust in v2, and eventually we reach a compromise.

> 
> > +	return page_rmappable_folio(page);
> 
> I don't particularly object to the main thrust of this patch.  I'm not
> sure I like it in huge_mm.h though.  Maybe in mm/internal.h?  I
> wouldn't want anyone outside mm/ calling it.

I was expecting more resistance :)  Right, I put it in huge_mm.h to be
next to your folio_prep_large_rmappable() declaration, but it doesn't
have to be there.  Ooh, there's a folio_undo_large_rmappable() in
mm/internal.h, I'll move page_rmappable_folio() next to that.

Hugh
diff mbox series

Patch

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index fa0350b0812a..58e7662a8a62 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -141,6 +141,15 @@  unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags);
 
 void folio_prep_large_rmappable(struct folio *folio);
+static inline struct folio *page_rmappable_folio(struct page *page)
+{
+	struct folio *folio = (struct folio *)page;
+
+	if (folio && folio_order(folio) > 1)
+		folio_prep_large_rmappable(folio);
+	return folio;
+}
+
 bool can_split_folio(struct folio *folio, int *pextra_pins);
 int split_huge_page_to_list(struct page *page, struct list_head *list);
 static inline int split_huge_page(struct page *page)
@@ -281,6 +290,10 @@  static inline bool hugepage_vma_check(struct vm_area_struct *vma,
 }
 
 static inline void folio_prep_large_rmappable(struct folio *folio) {}
+static inline struct folio *page_rmappable_folio(struct page *page)
+{
+	return (struct folio *)page;
+}
 
 #define transparent_hugepage_flags 0UL
 
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 7ab6102d7da4..4c3b3f535630 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2137,10 +2137,7 @@  struct folio *vma_alloc_folio(gfp_t gfp, int order, struct vm_area_struct *vma,
 		mpol_cond_put(pol);
 		gfp |= __GFP_COMP;
 		page = alloc_page_interleave(gfp, order, nid);
-		folio = (struct folio *)page;
-		if (folio && order > 1)
-			folio_prep_large_rmappable(folio);
-		goto out;
+		return page_rmappable_folio(page);
 	}
 
 	if (pol->mode == MPOL_PREFERRED_MANY) {
@@ -2150,10 +2147,7 @@  struct folio *vma_alloc_folio(gfp_t gfp, int order, struct vm_area_struct *vma,
 		gfp |= __GFP_COMP;
 		page = alloc_pages_preferred_many(gfp, order, node, pol);
 		mpol_cond_put(pol);
-		folio = (struct folio *)page;
-		if (folio && order > 1)
-			folio_prep_large_rmappable(folio);
-		goto out;
+		return page_rmappable_folio(page);
 	}
 
 	if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
@@ -2247,12 +2241,7 @@  EXPORT_SYMBOL(alloc_pages);
 
 struct folio *folio_alloc(gfp_t gfp, unsigned order)
 {
-	struct page *page = alloc_pages(gfp | __GFP_COMP, order);
-	struct folio *folio = (struct folio *)page;
-
-	if (folio && order > 1)
-		folio_prep_large_rmappable(folio);
-	return folio;
+	return page_rmappable_folio(alloc_pages(gfp | __GFP_COMP, order));
 }
 EXPORT_SYMBOL(folio_alloc);
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 95546f376302..5b1707d9025a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4456,12 +4456,8 @@  struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
 		nodemask_t *nodemask)
 {
 	struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
-			preferred_nid, nodemask);
-	struct folio *folio = (struct folio *)page;
-
-	if (folio && order > 1)
-		folio_prep_large_rmappable(folio);
-	return folio;
+					  preferred_nid, nodemask);
+	return page_rmappable_folio(page);
 }
 EXPORT_SYMBOL(__folio_alloc);