The patch titled
Subject: powerpc: remove superfluous PageTail checks on the pte gup_fast
has been added to the -mm tree. Its filename is
powerpc-remove-superfluous-pagetail-checks-on-the-pte-gup_fast.patch
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------------------------------------------------------
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Subject: powerpc: remove superfluous PageTail checks on the pte gup_fast
This part of gup_fast doesn't seem capable of handling hugetlbfs ptes,
those should be handled by gup_hugepd only, so these checks are
superfluous.
Plus if this wasn't a noop, it would have oopsed because, the insistence
of using the speculative refcounting would trigger a VM_BUG_ON if a tail
page was encountered in the page_cache_get_speculative().
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxx>
---
arch/powerpc/mm/gup.c | 13 -------------
1 file changed, 13 deletions(-)
diff -puN arch/powerpc/mm/gup.c~powerpc-remove-superfluous-pagetail-checks-on-the-pte-gup_fast arch/powerpc/mm/gup.c
--- a/arch/powerpc/mm/gup.c~powerpc-remove-superfluous-pagetail-checks-on-the-pte-gup_fast
+++ a/arch/powerpc/mm/gup.c
@@ -16,17 +16,6 @@
#ifdef __HAVE_ARCH_PTE_SPECIAL
-static inline void get_huge_page_tail(struct page *page)
-{
- /*
- * __split_huge_page_refcount() cannot run
- * from under us.
- */
- VM_BUG_ON(page_mapcount(page) < 0);
- VM_BUG_ON(atomic_read(&page->_count) != 0);
- atomic_inc(&page->_mapcount);
-}
-
/*
* The performance critical leaf functions are made noinline otherwise gcc
* inlines everything into a single function which results in too much
@@ -58,8 +47,6 @@ static noinline int gup_pte_range(pmd_t
put_page(page);
return 0;
}
- if (PageTail(page))
- get_huge_page_tail(page);
pages[*nr] = page;
(*nr)++;
_
Subject: Subject: powerpc: remove superfluous PageTail checks on the pte gup_fast
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
mm-compaction-trivial-clean-up-in-acct_isolated.patch
mm-change-isolate-mode-from-define-to-bitwise-type.patch
mm-compaction-make-isolate_lru_page-filter-aware.patch
mm-compaction-make-isolate_lru_page-filter-aware-fix.patch
mm-zone_reclaim-make-isolate_lru_page-filter-aware.patch
mm-zone_reclaim-make-isolate_lru_page-filter-aware-fix.patch
mm-migration-clean-up-unmap_and_move.patch
mremap-check-for-overflow-using-deltas.patch
mremap-avoid-sending-one-ipi-per-page.patch
thp-mremap-support-and-tlb-optimization.patch
thp-mremap-support-and-tlb-optimization-fix.patch
thp-mremap-support-and-tlb-optimization-fix-fix.patch
thp-mremap-support-and-tlb-optimization-fix-fix-fix.patch
thp-tail-page-refcounting-fix-5.patch
powerpc-remove-superfluous-pagetail-checks-on-the-pte-gup_fast.patch
powerpc-get_hugepte-dont-put_page-the-wrong-page.patch
powerpc-gup_hugepte-avoid-to-free-the-head-page-too-many-times.patch
powerpc-gup_hugepte-support-thp-based-tail-recounting.patch
mm-mempolicyc-quiet-sparse-noise.patch
mm-huge_memoryc-quiet-sparse-noise.patch
vmscan-limit-direct-reclaim-for-higher-order-allocations.patch
vmscan-limit-direct-reclaim-for-higher-order-allocations-fix.patch
vmscan-abort-reclaim-compaction-if-compaction-can-proceed.patch
mm-huge_memory-fix-copying-user-highpage.patch
mm-huge_memory-fix-typo-when-updating-mmu-cache.patch
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