On 10 Mar 2025, at 13:32, Zi Yan wrote: > On 10 Mar 2025, at 12:14, Zi Yan wrote: > >> On 7 Mar 2025, at 12:39, Zi Yan wrote: >> >>> This is a preparation patch, both added functions are not used yet. >>> >>> The added __split_unmapped_folio() is able to split a folio with its >>> mapping removed in two manners: 1) uniform split (the existing way), and >>> 2) buddy allocator like (or non-uniform) split. >>> >>> The added __split_folio_to_order() can split a folio into any lower order. >>> For uniform split, __split_unmapped_folio() calls it once to split the >>> given folio to the new order. For buddy allocator like (non-uniform) >>> split, __split_unmapped_folio() calls it (folio_order - new_order) times >>> and each time splits the folio containing the given page to one lower >>> order. >>> >>> Signed-off-by: Zi Yan <z...@nvidia.com> >>> Cc: Baolin Wang <baolin.w...@linux.alibaba.com> >>> Cc: David Hildenbrand <da...@redhat.com> >>> Cc: Hugh Dickins <hu...@google.com> >>> Cc: John Hubbard <jhubb...@nvidia.com> >>> Cc: Kefeng Wang <wangkefeng.w...@huawei.com> >>> Cc: Kirill A. Shuemov <kirill.shute...@linux.intel.com> >>> Cc: Matthew Wilcox <wi...@infradead.org> >>> Cc: Miaohe Lin <linmia...@huawei.com> >>> Cc: Ryan Roberts <ryan.robe...@arm.com> >>> Cc: Yang Shi <y...@os.amperecomputing.com> >>> Cc: Yu Zhao <yuz...@google.com> >>> Cc: Kairui Song <kas...@tencent.com> >>> --- >>> mm/huge_memory.c | 348 ++++++++++++++++++++++++++++++++++++++++++++++- >>> 1 file changed, 347 insertions(+), 1 deletion(-) >> >> Hi Andrew, >> >> The patch below should fix the issues discovered by Hugh. Please fold >> it into this patch. Thank you for all the help. >> > > Hi Andrew, > > This is the updated version including: > 1. Hugh’s fix on unfreezing head folio correctly, > 2. Hugh’s fix on drop the right number of refs on tail folio, > 3. Matthew’s suggestion on using new_folio instead of new_head and > using i instead of index. >
Hi Andrew, The fixup below should get rid of the sparse warning. >From 83472fe89330a262facba427051426e8cd13e218 Mon Sep 17 00:00:00 2001 From: Zi Yan <z...@nvidia.com> Date: Thu, 13 Mar 2025 10:04:20 -0400 Subject: [PATCH] mm/huge_memory: use NULL instead of 0 for folio->private assignment. It makes sparse happy. Reported-by: kernel test robot <l...@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202503131109.s7iuwfgq-...@intel.com/ Signed-off-by: Zi Yan <z...@nvidia.com> --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 14b1963898a7..e3ed8e9523f5 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3369,7 +3369,7 @@ static void __split_folio_to_order(struct folio *folio, int old_order, */ if (unlikely(new_folio->private)) { VM_WARN_ON_ONCE_PAGE(true, new_head); - new_folio->private = 0; + new_folio->private = NULL; } if (folio_test_swapcache(folio)) -- 2.47.2 Best Regards, Yan, Zi
