+ mm-use-aligned-address-in-clear_gigantic_page.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: use aligned address in clear_gigantic_page()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-use-aligned-address-in-clear_gigantic_page.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-use-aligned-address-in-clear_gigantic_page.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: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm: use aligned address in clear_gigantic_page()
Date: Sat, 26 Oct 2024 13:43:06 +0800

When clearing gigantic page, it zeros page from the first page to the last
page, if directly passing addr_hint which maybe not the address of the
first page of folio, then some archs could flush the wrong cache if it
does use the addr_hint as a hint.  For non-gigantic page, it calculates
the base address inside, even passed the wrong addr_hint, it only has
performance impact as the process_huge_page() wants to process target page
last to keep its cache lines hot), no functional impact.

Let's pass the real accessed address to folio_zero_user() and use the
aligned address in clear_gigantic_page() to fix it.

Link: https://lkml.kernel.org/r/20241026054307.3896926-1-wangkefeng.wang@huawei.com
Fixes: 78fefd04c123 ("mm: memory: convert clear_huge_page() to folio_zero_user()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/hugetlbfs/inode.c |    2 +-
 mm/memory.c          |    1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

--- a/fs/hugetlbfs/inode.c~mm-use-aligned-address-in-clear_gigantic_page
+++ a/fs/hugetlbfs/inode.c
@@ -819,7 +819,7 @@ static long hugetlbfs_fallocate(struct f
 			error = PTR_ERR(folio);
 			goto out;
 		}
-		folio_zero_user(folio, ALIGN_DOWN(addr, hpage_size));
+		folio_zero_user(folio, addr);
 		__folio_mark_uptodate(folio);
 		error = hugetlb_add_to_page_cache(folio, mapping, index);
 		if (unlikely(error)) {
--- a/mm/memory.c~mm-use-aligned-address-in-clear_gigantic_page
+++ a/mm/memory.c
@@ -6810,6 +6810,7 @@ static void clear_gigantic_page(struct f
 	int i;
 
 	might_sleep();
+	addr = ALIGN_DOWN(addr, folio_size(folio));
 	for (i = 0; i < nr_pages; i++) {
 		cond_resched();
 		clear_user_highpage(folio_page(folio, i), addr + i * PAGE_SIZE);
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

mm-remove-unused-hugepage-for-vma_alloc_folio.patch
tmpfs-dont-enable-large-folios-if-not-supported.patch
mm-huge_memory-move-file_thp_enabled-into-huge_memoryc.patch
mm-shmem-remove-__shmem_huge_global_enabled.patch
mm-use-aligned-address-in-clear_gigantic_page.patch
mm-use-aligned-address-in-copy_user_gigantic_page.patch