From cfeed8ffe55b37fa10286aaaa1369da00cb88440 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 21 Aug 2023 18:08:46 +0200 Subject: mm/swap: stop using page->private on tail pages for THP_SWAP Patch series "mm/swap: stop using page->private on tail pages for THP_SWAP + cleanups". This series stops using page->private on tail pages for THP_SWAP, replaces folio->private by folio->swap for swapcache folios, and starts using "new_folio" for tail pages that we are splitting to remove the usage of page->private for swapcache handling completely. This patch (of 4): Let's stop using page->private on tail pages, making it possible to just unconditionally reuse that field in the tail pages of large folios. The remaining usage of the private field for THP_SWAP is in the THP splitting code (mm/huge_memory.c), that we'll handle separately later. Update the THP_SWAP documentation and sanity checks in mm_types.h and __split_huge_page_tail(). [david@redhat.com: stop using page->private on tail pages for THP_SWAP] Link: https://lkml.kernel.org/r/6f0a82a3-6948-20d9-580b-be1dbf415701@redhat.com Link: https://lkml.kernel.org/r/20230821160849.531668-1-david@redhat.com Link: https://lkml.kernel.org/r/20230821160849.531668-2-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Catalin Marinas [arm64] Reviewed-by: Yosry Ahmed Cc: Dan Streetman Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Seth Jennings Cc: Vitaly Wool Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm64/mm/mteswap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c index cd508ba80ab1..a31833e3ddc5 100644 --- a/arch/arm64/mm/mteswap.c +++ b/arch/arm64/mm/mteswap.c @@ -33,8 +33,9 @@ int mte_save_tags(struct page *page) mte_save_page_tags(page_address(page), tag_storage); - /* page_private contains the swap entry.val set in do_swap_page */ - ret = xa_store(&mte_pages, page_private(page), tag_storage, GFP_KERNEL); + /* lookup the swap entry.val from the page */ + ret = xa_store(&mte_pages, page_swap_entry(page).val, tag_storage, + GFP_KERNEL); if (WARN(xa_is_err(ret), "Failed to store MTE tags")) { mte_free_tag_storage(tag_storage); return xa_err(ret); -- cgit v1.2.3