The patch titled
Subject: mm, THP, swap: support PMD swap mapping in madvise_free()
has been added to the -mm tree. Its filename is
mm-thp-swap-support-pmd-swap-mapping-in-madvise_free.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-thp-swap-support-pmd-swap-mapping-in-madvise_free.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-swap-support-pmd-swap-mapping-in-madvise_free.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Huang Ying <ying.huang@xxxxxxxxx>
Subject: mm, THP, swap: support PMD swap mapping in madvise_free()
When madvise_free() found a PMD swap mapping, if only part of the huge
swap cluster is operated on, the PMD swap mapping will be split and
fallback to PTE swap mapping processing. Otherwise, if all huge swap
cluster is operated on, free_swap_and_cache() will be called to decrease
the PMD swap mapping count and probably free the swap space and the THP in
swap cache too.
Link: http://lkml.kernel.org/r/20180622035151.6676-14-ying.huang@xxxxxxxxx
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Shaohua Li <shli@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN mm/huge_memory.c~mm-thp-swap-support-pmd-swap-mapping-in-madvise_free mm/huge_memory.c
--- a/mm/huge_memory.c~mm-thp-swap-support-pmd-swap-mapping-in-madvise_free
+++ a/mm/huge_memory.c
@@ -1843,6 +1843,15 @@ static inline void __split_huge_swap_pmd
}
#endif
+static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
+ pte_free(mm, pgtable);
+ mm_dec_nr_ptes(mm);
+}
+
/*
* Return true if we do MADV_FREE successfully on entire pmd page.
* Otherwise, return false.
@@ -1863,15 +1872,35 @@ bool madvise_free_huge_pmd(struct mmu_ga
goto out_unlocked;
orig_pmd = *pmd;
- if (is_huge_zero_pmd(orig_pmd))
- goto out;
-
if (unlikely(!pmd_present(orig_pmd))) {
- VM_BUG_ON(thp_migration_supported() &&
- !is_pmd_migration_entry(orig_pmd));
- goto out;
+ swp_entry_t entry = pmd_to_swp_entry(orig_pmd);
+
+ if (is_migration_entry(entry)) {
+ VM_BUG_ON(!thp_migration_supported());
+ goto out;
+ } else if (thp_swap_supported() && !non_swap_entry(entry)) {
+ /* If part of THP is discarded */
+ if (next - addr != HPAGE_PMD_SIZE) {
+ unsigned long haddr = addr & HPAGE_PMD_MASK;
+
+ __split_huge_swap_pmd(vma, haddr, pmd);
+ goto out;
+ }
+ free_swap_and_cache(entry, true);
+ pmd_clear(pmd);
+ zap_deposited_table(mm, pmd);
+ if (current->mm == mm)
+ sync_mm_rss(mm);
+ add_mm_counter(mm, MM_SWAPENTS, -HPAGE_PMD_NR);
+ ret = true;
+ goto out;
+ } else
+ VM_BUG_ON(1);
}
+ if (is_huge_zero_pmd(orig_pmd))
+ goto out;
+
page = pmd_page(orig_pmd);
/*
* If other processes are mapping this page, we couldn't discard
@@ -1917,15 +1946,6 @@ out_unlocked:
return ret;
}
-static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd)
-{
- pgtable_t pgtable;
-
- pgtable = pgtable_trans_huge_withdraw(mm, pmd);
- pte_free(mm, pgtable);
- mm_dec_nr_ptes(mm);
-}
-
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
diff -puN mm/madvise.c~mm-thp-swap-support-pmd-swap-mapping-in-madvise_free mm/madvise.c
--- a/mm/madvise.c~mm-thp-swap-support-pmd-swap-mapping-in-madvise_free
+++ a/mm/madvise.c
@@ -321,7 +321,7 @@ static int madvise_free_pte_range(pmd_t
unsigned long next;
next = pmd_addr_end(addr, end);
- if (pmd_trans_huge(*pmd))
+ if (pmd_trans_huge(*pmd) || is_swap_pmd(*pmd))
if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next))
goto next;
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
mm-clear_huge_page-move-order-algorithm-into-a-separate-function.patch
mm-huge-page-copy-target-sub-page-last-when-copy-huge-page.patch
mm-hugetlbfs-rename-address-to-haddr-in-hugetlb_cow.patch
mm-hugetlbfs-pass-fault-address-to-cow-handler.patch
mm-swap-fix-race-between-swapoff-and-some-swap-operations.patch
mm-swap-fix-race-between-swapoff-and-some-swap-operations-v6.patch
mm-fix-race-between-swapoff-and-mincore.patch
mm-thp-swap-enable-pmd-swap-operations-for-config_thp_swap.patch
mm-thp-swap-make-config_thp_swap-depends-on-config_swap.patch
mm-thp-swap-support-pmd-swap-mapping-in-swap_duplicate.patch
mm-thp-swap-support-pmd-swap-mapping-in-swapcache_free_cluster.patch
mm-thp-swap-support-pmd-swap-mapping-in-free_swap_and_cache-swap_free.patch
mm-thp-swap-support-pmd-swap-mapping-when-splitting-huge-pmd.patch
mm-thp-swap-support-pmd-swap-mapping-in-split_swap_cluster.patch
mm-thp-swap-support-to-read-a-huge-swap-cluster-for-swapin-a-thp.patch
mm-thp-swap-swapin-a-thp-as-a-whole.patch
mm-thp-swap-support-to-count-thp-swapin-and-its-fallback.patch
mm-thp-swap-add-sysfs-interface-to-configure-thp-swapin.patch
mm-thp-swap-support-pmd-swap-mapping-in-swapoff.patch
mm-thp-swap-support-pmd-swap-mapping-in-madvise_free.patch
mm-cgroup-thp-swap-support-to-move-swap-account-for-pmd-swap-mapping.patch
mm-thp-swap-support-to-copy-pmd-swap-mapping-when-fork.patch
mm-thp-swap-free-pmd-swap-mapping-when-zap_huge_pmd.patch
mm-thp-swap-support-pmd-swap-mapping-for-madv_willneed.patch
mm-thp-swap-support-pmd-swap-mapping-in-mincore.patch
mm-thp-swap-support-pmd-swap-mapping-in-common-path.patch
mm-thp-swap-create-pmd-swap-mapping-when-unmap-the-thp.patch
mm-thp-avoid-to-split-thp-when-reclaim-madv_free-thp.patch
--
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