The patch titled
Subject: mm: optimise pte dirty/accessed bit setting by demand based pte insertion
has been added to the -mm tree. Its filename is
mm-optimise-pte-dirty-accessed-bit-setting-by-demand-based-pte-insertion.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-optimise-pte-dirty-accessed-bit-setting-by-demand-based-pte-insertion.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-optimise-pte-dirty-accessed-bit-setting-by-demand-based-pte-insertion.patch
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------------------------------------------------------
From: Nicholas Piggin <npiggin@xxxxxxxxx>
Subject: mm: optimise pte dirty/accessed bit setting by demand based pte insertion
Similarly to the previous patch, this tries to optimise dirty/accessed
bits in ptes to avoid access costs of hardware setting them.
Link: http://lkml.kernel.org/r/20180828112034.30875-4-npiggin@xxxxxxxxx
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 12 +++++++-----
mm/memory.c | 8 +++++---
2 files changed, 12 insertions(+), 8 deletions(-)
--- a/mm/huge_memory.c~mm-optimise-pte-dirty-accessed-bit-setting-by-demand-based-pte-insertion
+++ a/mm/huge_memory.c
@@ -1197,6 +1197,7 @@ static vm_fault_t do_huge_pmd_wp_page_fa
for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
pte_t entry;
entry = mk_pte(pages[i], vma->vm_page_prot);
+ entry = pte_mkyoung(entry);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
memcg = (void *)page_private(pages[i]);
set_page_private(pages[i], 0);
@@ -2067,7 +2068,7 @@ static void __split_huge_pmd_locked(stru
struct page *page;
pgtable_t pgtable;
pmd_t old_pmd, _pmd;
- bool young, write, soft_dirty, pmd_migration = false;
+ bool young, write, dirty, soft_dirty, pmd_migration = false;
unsigned long addr;
int i;
@@ -2145,8 +2146,7 @@ static void __split_huge_pmd_locked(stru
page = pmd_page(old_pmd);
VM_BUG_ON_PAGE(!page_count(page), page);
page_ref_add(page, HPAGE_PMD_NR - 1);
- if (pmd_dirty(old_pmd))
- SetPageDirty(page);
+ dirty = pmd_dirty(old_pmd);
write = pmd_write(old_pmd);
young = pmd_young(old_pmd);
soft_dirty = pmd_soft_dirty(old_pmd);
@@ -2176,8 +2176,10 @@ static void __split_huge_pmd_locked(stru
entry = maybe_mkwrite(entry, vma);
if (!write)
entry = pte_wrprotect(entry);
- if (!young)
- entry = pte_mkold(entry);
+ if (young)
+ entry = pte_mkyoung(entry);
+ if (dirty)
+ entry = pte_mkdirty(entry);
if (soft_dirty)
entry = pte_mksoft_dirty(entry);
}
--- a/mm/memory.c~mm-optimise-pte-dirty-accessed-bit-setting-by-demand-based-pte-insertion
+++ a/mm/memory.c
@@ -1801,10 +1801,9 @@ static vm_fault_t insert_pfn(struct vm_a
entry = pte_mkspecial(pfn_t_pte(pfn, prot));
out_mkwrite:
- if (mkwrite) {
- entry = pte_mkyoung(entry);
+ entry = pte_mkyoung(entry);
+ if (mkwrite)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- }
set_pte_at(mm, addr, pte, entry);
update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
@@ -2532,6 +2531,7 @@ static vm_fault_t wp_page_copy(struct vm
}
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
+ entry = pte_mkyoung(entry);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
/*
* Clear the pte entry and flush it first, before updating the
@@ -3041,6 +3041,7 @@ vm_fault_t do_swap_page(struct vm_fault
inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
dec_mm_counter_fast(vma->vm_mm, MM_SWAPENTS);
pte = mk_pte(page, vma->vm_page_prot);
+ pte = pte_mkyoung(pte);
if ((vmf->flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
vmf->flags &= ~FAULT_FLAG_WRITE;
@@ -3451,6 +3452,7 @@ vm_fault_t alloc_set_pte(struct vm_fault
flush_icache_page(vma, page);
entry = mk_pte(page, vma->vm_page_prot);
+ entry = pte_mkyoung(entry);
if (write)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
/* copy-on-write page */
_
Patches currently in -mm which might be from npiggin@xxxxxxxxx are
mm-cow-dont-bother-write-protectig-already-write-protected-huge-pages.patch
mm-cow-optimise-pte-dirty-accessed-bits-handling-in-fork.patch
mm-optimise-pte-dirty-accessed-bit-setting-by-demand-based-pte-insertion.patch
