+ mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook.patch added to mm-unstable branch

+ mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/page_alloc: forward the gfp flags from alloc_contig_range() to post_alloc_hook()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
Subject: mm/page_alloc: forward the gfp flags from alloc_contig_range() to post_alloc_hook()
Date: Tue, 3 Dec 2024 10:47:31 +0100

In the __GFP_COMP case, we already pass the gfp_flags to
prep_new_page()->post_alloc_hook().  However, in the !__GFP_COMP case, we
essentially pass only hardcoded __GFP_MOVABLE to post_alloc_hook(),
preventing some action modifiers from being effective..

Let's pass our now properly adjusted gfp flags there as well.

This way, we can now support __GFP_ZERO for alloc_contig_*().

As a side effect, we now also support __GFP_SKIP_ZERO and__GFP_ZEROTAGS;
but we'll keep the more special stuff (KASAN, NOLOCKDEP) disabled for now.

It's worth noting that with __GFP_ZERO, we might unnecessarily zero pages
when we have to release part of our range using free_contig_range() again.
This can be optimized in the future, if ever required; the caller we'll
be converting (powernv/memtrace) next won't trigger this.

Link: https://lkml.kernel.org/r/20241203094732.200195-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/mm/page_alloc.c~mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook
+++ a/mm/page_alloc.c
@@ -6358,7 +6358,7 @@ static int __alloc_contig_migrate_range(
 	return (ret < 0) ? ret : 0;
 }
 
-static void split_free_pages(struct list_head *list)
+static void split_free_pages(struct list_head *list, gfp_t gfp_mask)
 {
 	int order;
 
@@ -6369,7 +6369,7 @@ static void split_free_pages(struct list
 		list_for_each_entry_safe(page, next, &list[order], lru) {
 			int i;
 
-			post_alloc_hook(page, order, __GFP_MOVABLE);
+			post_alloc_hook(page, order, gfp_mask);
 			set_page_refcounted(page);
 			if (!order)
 				continue;
@@ -6387,7 +6387,8 @@ static void split_free_pages(struct list
 static int __alloc_contig_verify_gfp_mask(gfp_t gfp_mask, gfp_t *gfp_cc_mask)
 {
 	const gfp_t reclaim_mask = __GFP_IO | __GFP_FS | __GFP_RECLAIM;
-	const gfp_t action_mask = __GFP_COMP | __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
+	const gfp_t action_mask = __GFP_COMP | __GFP_RETRY_MAYFAIL | __GFP_NOWARN |
+				  __GFP_ZERO | __GFP_ZEROTAGS | __GFP_SKIP_ZERO;
 	const gfp_t cc_action_mask = __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
 
 	/*
@@ -6535,7 +6536,7 @@ int alloc_contig_range_noprof(unsigned l
 	}
 
 	if (!(gfp_mask & __GFP_COMP)) {
-		split_free_pages(cc.freepages);
+		split_free_pages(cc.freepages, gfp_mask);
 
 		/* Free head and tail (if any) */
 		if (start != outer_start)
_

Patches currently in -mm which might be from david@redhat.com are

mm-mempolicy-fix-migrate_to_node-assuming-there-is-at-least-one-vma-in-a-mm.patch
mm-filemap-dont-call-folio_test_locked-without-a-reference-in-next_uptodate_folio.patch
docs-tmpfs-update-the-large-folios-policy-for-tmpfs-and-shmem.patch
mm-memory_hotplug-move-debug_pagealloc_map_pages-into-online_pages_range.patch
mm-page_isolation-dont-pass-gfp-flags-to-isolate_single_pageblock.patch
mm-page_isolation-dont-pass-gfp-flags-to-start_isolate_page_range.patch
mm-page_alloc-make-__alloc_contig_migrate_range-static.patch
mm-page_alloc-sort-out-the-alloc_contig_range-gfp-flags-mess.patch
mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook.patch
powernv-memtrace-use-__gfp_zero-with-alloc_contig_pages.patch