The patch titled
thp: mprotect: transparent huge page support
has been added to the -mm tree. Its filename is
thp-mprotect-transparent-huge-page-support.patch
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------------------------------------------------------
Subject: thp: mprotect: transparent huge page support
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Natively handle huge pmds when changing page tables on behalf of
mprotect().
I left out update_mmu_cache() because we do not need it on x86 anyway but
more importantly the interface works on ptes, not pmds.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/huge_mm.h | 2 ++
mm/huge_memory.c | 27 +++++++++++++++++++++++++++
mm/mprotect.c | 8 +++++++-
3 files changed, 36 insertions(+), 1 deletion(-)
diff -puN include/linux/huge_mm.h~thp-mprotect-transparent-huge-page-support include/linux/huge_mm.h
--- a/include/linux/huge_mm.h~thp-mprotect-transparent-huge-page-support
+++ a/include/linux/huge_mm.h
@@ -22,6 +22,8 @@ extern int zap_huge_pmd(struct mmu_gathe
extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
unsigned char *vec);
+extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, pgprot_t newprot);
enum transparent_hugepage_flag {
TRANSPARENT_HUGEPAGE_FLAG,
diff -puN mm/huge_memory.c~thp-mprotect-transparent-huge-page-support mm/huge_memory.c
--- a/mm/huge_memory.c~thp-mprotect-transparent-huge-page-support
+++ a/mm/huge_memory.c
@@ -948,6 +948,33 @@ int mincore_huge_pmd(struct vm_area_stru
return ret;
}
+int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, pgprot_t newprot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int ret = 0;
+
+ spin_lock(&mm->page_table_lock);
+ if (likely(pmd_trans_huge(*pmd))) {
+ if (unlikely(pmd_trans_splitting(*pmd))) {
+ spin_unlock(&mm->page_table_lock);
+ wait_split_huge_page(vma->anon_vma, pmd);
+ } else {
+ pmd_t entry;
+
+ entry = pmdp_get_and_clear(mm, addr, pmd);
+ entry = pmd_modify(entry, newprot);
+ set_pmd_at(mm, addr, pmd, entry);
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ flush_tlb_range(vma, addr, addr + HPAGE_PMD_SIZE);
+ ret = 1;
+ }
+ } else
+ spin_unlock(&vma->vm_mm->page_table_lock);
+
+ return ret;
+}
+
pmd_t *page_check_address_pmd(struct page *page,
struct mm_struct *mm,
unsigned long address,
diff -puN mm/mprotect.c~thp-mprotect-transparent-huge-page-support mm/mprotect.c
--- a/mm/mprotect.c~thp-mprotect-transparent-huge-page-support
+++ a/mm/mprotect.c
@@ -88,7 +88,13 @@ static inline void change_pmd_range(stru
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
- split_huge_page_pmd(vma->vm_mm, pmd);
+ if (pmd_trans_huge(*pmd)) {
+ if (next - addr != HPAGE_PMD_SIZE)
+ split_huge_page_pmd(vma->vm_mm, pmd);
+ else if (change_huge_pmd(vma, pmd, addr, newprot))
+ continue;
+ /* fall through */
+ }
if (pmd_none_or_clear_bad(pmd))
continue;
change_pte_range(vma->vm_mm, pmd, addr, next, newprot,
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-compactionc-avoid-double-mem_cgroup_del_lru.patch
writeback-integrated-background-writeback-work.patch
writeback-trace-wakeup-event-for-background-writeback.patch
writeback-stop-background-kupdate-works-from-livelocking-other-works.patch
writeback-stop-background-kupdate-works-from-livelocking-other-works-update.patch
writeback-avoid-livelocking-wb_sync_all-writeback.patch
writeback-avoid-livelocking-wb_sync_all-writeback-update.patch
writeback-check-skipped-pages-on-wb_sync_all.patch
writeback-check-skipped-pages-on-wb_sync_all-update.patch
writeback-check-skipped-pages-on-wb_sync_all-update-fix.patch
mm-compaction-add-trace-events-for-memory-compaction-activity.patch
mm-vmscan-convert-lumpy_mode-into-a-bitmask.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-fix.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path-fix.patch
mm-migration-cleanup-migrate_pages-api-by-matching-types-for-offlining-and-sync.patch
mm-compaction-perform-a-faster-migration-scan-when-migrating-asynchronously.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode-fix.patch
mm-deactivate-invalidated-pages.patch
mm-deactivate-invalidated-pages-fix.patch
mm-kswapd-stop-high-order-balancing-when-any-suitable-zone-is-balanced.patch
mm-kswapd-keep-kswapd-awake-for-high-order-allocations-until-a-percentage-of-the-node-is-balanced.patch
mm-kswapd-use-the-order-that-kswapd-was-reclaiming-at-for-sleeping_prematurely.patch
mm-kswapd-reset-kswapd_max_order-and-classzone_idx-after-reading.patch
mm-kswapd-treat-zone-all_unreclaimable-in-sleeping_prematurely-similar-to-balance_pgdat.patch
mm-kswapd-use-the-classzone-idx-that-kswapd-was-using-for-sleeping_prematurely.patch
thp-split_huge_page_mm-vma.patch
thp-transparent-hugepage-core.patch
thp-add-x86-32bit-support.patch
thp-mincore-transparent-hugepage-support.patch
thp-add-pmd_modify.patch
thp-mprotect-pass-vma-down-to-page-table-walkers.patch
thp-mprotect-transparent-huge-page-support.patch
memcg-fix-unit-mismatch-in-memcg-oom-limit-calculation.patch
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