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authorDavid Hildenbrand <david@redhat.com>2023-12-20 23:44:27 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-12-29 11:58:47 -0800
commit44887f39945519fa8405133b1acd098fda9c9746 (patch)
treef753041d11b1e3de1d51f853c680b1c43da78cf6 /mm/rmap.c
parente135826b2da0cf25305086dc9ac1e91718a148e1 (diff)
mm/rmap: introduce and use hugetlb_add_file_rmap()
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Right now we're using page_dup_file_rmap() in some cases where "ordinary" rmap code would have used page_add_file_rmap(). So let's introduce and use hugetlb_add_file_rmap() instead. We won't be adding a "hugetlb_dup_file_rmap()" functon for the fork() case, as it would be doing the same: "dup" is just an optimization for "add". What remains is a single page_dup_file_rmap() call in fork() code. Add sanity checks that we end up with the right folios in the right functions. Link: https://lkml.kernel.org/r/20231220224504.646757-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 261e1af0d254..a57ec926daf0 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1395,6 +1395,7 @@ void folio_add_file_rmap_range(struct folio *folio, struct page *page,
unsigned int nr_pmdmapped = 0, first;
int nr = 0;
+ VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
VM_WARN_ON_FOLIO(compound && !folio_test_pmd_mappable(folio), folio);
/* Is page being mapped by PTE? Is this its first map to be added? */