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-rw-r--r--kernel/mm/hugetlb.c19
-rw-r--r--kernel/mm/memory-failure.c15
-rw-r--r--kernel/mm/memory.c20
-rw-r--r--kernel/mm/vmscan.c14
4 files changed, 37 insertions, 31 deletions
diff --git a/kernel/mm/hugetlb.c b/kernel/mm/hugetlb.c
index 271e44327..8c4c1f9f9 100644
--- a/kernel/mm/hugetlb.c
+++ b/kernel/mm/hugetlb.c
@@ -40,6 +40,11 @@ int hugepages_treat_as_movable;
int hugetlb_max_hstate __read_mostly;
unsigned int default_hstate_idx;
struct hstate hstates[HUGE_MAX_HSTATE];
+/*
+ * Minimum page order among possible hugepage sizes, set to a proper value
+ * at boot time.
+ */
+static unsigned int minimum_order __read_mostly = UINT_MAX;
__initdata LIST_HEAD(huge_boot_pages);
@@ -1188,19 +1193,13 @@ static void dissolve_free_huge_page(struct page *page)
*/
void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
{
- unsigned int order = 8 * sizeof(void *);
unsigned long pfn;
- struct hstate *h;
if (!hugepages_supported())
return;
- /* Set scan step to minimum hugepage size */
- for_each_hstate(h)
- if (order > huge_page_order(h))
- order = huge_page_order(h);
- VM_BUG_ON(!IS_ALIGNED(start_pfn, 1 << order));
- for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order)
+ VM_BUG_ON(!IS_ALIGNED(start_pfn, 1 << minimum_order));
+ for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order)
dissolve_free_huge_page(pfn_to_page(pfn));
}
@@ -1627,10 +1626,14 @@ static void __init hugetlb_init_hstates(void)
struct hstate *h;
for_each_hstate(h) {
+ if (minimum_order > huge_page_order(h))
+ minimum_order = huge_page_order(h);
+
/* oversize hugepages were init'ed in early boot */
if (!hstate_is_gigantic(h))
hugetlb_hstate_alloc_pages(h);
}
+ VM_BUG_ON(minimum_order == UINT_MAX);
}
static char * __init memfmt(char *buf, unsigned long n)
diff --git a/kernel/mm/memory-failure.c b/kernel/mm/memory-failure.c
index 501820c81..9f48145c8 100644
--- a/kernel/mm/memory-failure.c
+++ b/kernel/mm/memory-failure.c
@@ -1558,6 +1558,8 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
*/
ret = __get_any_page(page, pfn, 0);
if (!PageLRU(page)) {
+ /* Drop page reference which is from __get_any_page() */
+ put_page(page);
pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
pfn, page->flags);
return -EIO;
@@ -1587,13 +1589,12 @@ static int soft_offline_huge_page(struct page *page, int flags)
unlock_page(hpage);
ret = isolate_huge_page(hpage, &pagelist);
- if (ret) {
- /*
- * get_any_page() and isolate_huge_page() takes a refcount each,
- * so need to drop one here.
- */
- put_page(hpage);
- } else {
+ /*
+ * get_any_page() and isolate_huge_page() takes a refcount each,
+ * so need to drop one here.
+ */
+ put_page(hpage);
+ if (!ret) {
pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
return -EBUSY;
}
diff --git a/kernel/mm/memory.c b/kernel/mm/memory.c
index 17734c3c1..3fc6efd10 100644
--- a/kernel/mm/memory.c
+++ b/kernel/mm/memory.c
@@ -2669,6 +2669,10 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
pte_unmap(page_table);
+ /* File mapping without ->vm_ops ? */
+ if (vma->vm_flags & VM_SHARED)
+ return VM_FAULT_SIGBUS;
+
/* Check if we need to add a guard page to the stack */
if (check_stack_guard_page(vma, address) < 0)
return VM_FAULT_SIGSEGV;
@@ -3097,6 +3101,9 @@ static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
pte_unmap(page_table);
+ /* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */
+ if (!vma->vm_ops->fault)
+ return VM_FAULT_SIGBUS;
if (!(flags & FAULT_FLAG_WRITE))
return do_read_fault(mm, vma, address, pmd, pgoff, flags,
orig_pte);
@@ -3242,13 +3249,12 @@ static int handle_pte_fault(struct mm_struct *mm,
barrier();
if (!pte_present(entry)) {
if (pte_none(entry)) {
- if (vma->vm_ops) {
- if (likely(vma->vm_ops->fault))
- return do_fault(mm, vma, address, pte,
- pmd, flags, entry);
- }
- return do_anonymous_page(mm, vma, address,
- pte, pmd, flags);
+ if (vma->vm_ops)
+ return do_fault(mm, vma, address, pte, pmd,
+ flags, entry);
+
+ return do_anonymous_page(mm, vma, address, pte, pmd,
+ flags);
}
return do_swap_page(mm, vma, address,
pte, pmd, flags, entry);
diff --git a/kernel/mm/vmscan.c b/kernel/mm/vmscan.c
index 5e8eadd71..0d024fc8a 100644
--- a/kernel/mm/vmscan.c
+++ b/kernel/mm/vmscan.c
@@ -937,21 +937,17 @@ static unsigned long shrink_page_list(struct list_head *page_list,
*
* 2) Global reclaim encounters a page, memcg encounters a
* page that is not marked for immediate reclaim or
- * the caller does not have __GFP_IO. In this case mark
+ * the caller does not have __GFP_FS (or __GFP_IO if it's
+ * simply going to swap, not to fs). In this case mark
* the page for immediate reclaim and continue scanning.
*
- * __GFP_IO is checked because a loop driver thread might
+ * Require may_enter_fs because we would wait on fs, which
+ * may not have submitted IO yet. And the loop driver might
* enter reclaim, and deadlock if it waits on a page for
* which it is needed to do the write (loop masks off
* __GFP_IO|__GFP_FS for this reason); but more thought
* would probably show more reasons.
*
- * Don't require __GFP_FS, since we're not going into the
- * FS, just waiting on its writeback completion. Worryingly,
- * ext4 gfs2 and xfs allocate pages with
- * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so testing
- * may_enter_fs here is liable to OOM on them.
- *
* 3) memcg encounters a page that is not already marked
* PageReclaim. memcg does not have any dirty pages
* throttling so we could easily OOM just because too many
@@ -968,7 +964,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
/* Case 2 above */
} else if (global_reclaim(sc) ||
- !PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) {
+ !PageReclaim(page) || !may_enter_fs) {
/*
* This is slightly racy - end_page_writeback()
* might have just cleared PageReclaim, then