The patch titled
Subject: mm, THP, swap: support PMD swap mapping in mincore()
has been added to the -mm tree. Its filename is
mm-thp-swap-support-pmd-swap-mapping-in-mincore.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-thp-swap-support-pmd-swap-mapping-in-mincore.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-swap-support-pmd-swap-mapping-in-mincore.patch
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------------------------------------------------------
From: Huang Ying <ying.huang@xxxxxxxxx>
Subject: mm, THP, swap: support PMD swap mapping in mincore()
During mincore(), for PMD swap mapping, swap cache will be looked up. If
the resulting page isn't compound page, the PMD swap mapping will be split
and fallback to PTE swap mapping processing.
Link: http://lkml.kernel.org/r/20180622035151.6676-19-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/mincore.c~mm-thp-swap-support-pmd-swap-mapping-in-mincore mm/mincore.c
--- a/mm/mincore.c~mm-thp-swap-support-pmd-swap-mapping-in-mincore
+++ a/mm/mincore.c
@@ -48,7 +48,8 @@ static int mincore_hugetlb(pte_t *pte, u
* and is up to date; i.e. that no page-in operation would be required
* at this time if an application were to map and access this page.
*/
-static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
+static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff,
+ bool *compound)
{
unsigned char present = 0;
struct page *page;
@@ -86,6 +87,8 @@ static unsigned char mincore_page(struct
#endif
if (page) {
present = PageUptodate(page);
+ if (compound)
+ *compound = PageCompound(page);
put_page(page);
}
@@ -103,7 +106,8 @@ static int __mincore_unmapped_range(unsi
pgoff = linear_page_index(vma, addr);
for (i = 0; i < nr; i++, pgoff++)
- vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
+ vec[i] = mincore_page(vma->vm_file->f_mapping,
+ pgoff, NULL);
} else {
for (i = 0; i < nr; i++)
vec[i] = 0;
@@ -127,14 +131,36 @@ static int mincore_pte_range(pmd_t *pmd,
pte_t *ptep;
unsigned char *vec = walk->private;
int nr = (end - addr) >> PAGE_SHIFT;
+ swp_entry_t entry;
ptl = pmd_trans_huge_lock(pmd, vma);
if (ptl) {
- memset(vec, 1, nr);
+ unsigned char val = 1;
+ bool compound;
+
+ if (thp_swap_supported() && is_swap_pmd(*pmd)) {
+ entry = pmd_to_swp_entry(*pmd);
+ if (!non_swap_entry(entry)) {
+ val = mincore_page(swap_address_space(entry),
+ swp_offset(entry),
+ &compound);
+ /*
+ * The huge swap cluster has been
+ * split under us
+ */
+ if (!compound) {
+ __split_huge_swap_pmd(vma, addr, pmd);
+ spin_unlock(ptl);
+ goto fallback;
+ }
+ }
+ }
+ memset(vec, val, nr);
spin_unlock(ptl);
goto out;
}
+fallback:
if (pmd_trans_unstable(pmd)) {
__mincore_unmapped_range(addr, end, vma, vec);
goto out;
@@ -150,8 +176,7 @@ static int mincore_pte_range(pmd_t *pmd,
else if (pte_present(pte))
*vec = 1;
else { /* pte is a swap entry */
- swp_entry_t entry = pte_to_swp_entry(pte);
-
+ entry = pte_to_swp_entry(pte);
if (non_swap_entry(entry)) {
/*
* migration or hwpoison entries are always
@@ -161,7 +186,7 @@ static int mincore_pte_range(pmd_t *pmd,
} else {
#ifdef CONFIG_SWAP
*vec = mincore_page(swap_address_space(entry),
- swp_offset(entry));
+ swp_offset(entry), NULL);
#else
WARN_ON(1);
*vec = 1;
_
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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