x86, thp: remove infrastructure for handling splitting PMDs
With new refcounting we don't need to mark PMDs splitting. Let's drop
code to handle this.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index 65b0261..f8cb3e8 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -156,18 +156,7 @@
pmd_t pmd = *pmdp;
next = pmd_addr_end(addr, end);
- /*
- * The pmd_trans_splitting() check below explains why
- * pmdp_splitting_flush has to flush the tlb, to stop
- * this gup-fast code from running while we set the
- * splitting bit in the pmd. Returning zero will take
- * the slow path that will call wait_split_huge_page()
- * if the pmd is still in splitting state. gup-fast
- * can't because it has irq disabled and
- * wait_split_huge_page() would never return as the
- * tlb flush IPI wouldn't run.
- */
- if (pmd_none(pmd) || pmd_trans_splitting(pmd))
+ if (pmd_none(pmd))
return 0;
if (unlikely(pmd_large(pmd) || !pmd_present(pmd))) {
/*