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-rw-r--r--mm/cma.c4
-rw-r--r--mm/filemap.c23
-rw-r--r--mm/hugetlb.c2
-rw-r--r--mm/migrate.c13
-rw-r--r--mm/mremap.c23
-rw-r--r--mm/page_alloc.c2
6 files changed, 47 insertions, 20 deletions
diff --git a/mm/cma.c b/mm/cma.c
index 0463ad2ce06b..26ecff818881 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -339,13 +339,13 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
*/
if (base < highmem_start && limit > highmem_start) {
addr = memblock_alloc_range_nid(size, alignment,
- highmem_start, limit, nid, false);
+ highmem_start, limit, nid, true);
limit = highmem_start;
}
if (!addr) {
addr = memblock_alloc_range_nid(size, alignment, base,
- limit, nid, false);
+ limit, nid, true);
if (!addr) {
ret = -ENOMEM;
goto err;
diff --git a/mm/filemap.c b/mm/filemap.c
index f0ae9a6308cb..385759c4ce4b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2028,7 +2028,7 @@ find_page:
page = find_get_page(mapping, index);
if (!page) {
- if (iocb->ki_flags & IOCB_NOWAIT)
+ if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_NOIO))
goto would_block;
page_cache_sync_readahead(mapping,
ra, filp,
@@ -2038,6 +2038,10 @@ find_page:
goto no_cached_page;
}
if (PageReadahead(page)) {
+ if (iocb->ki_flags & IOCB_NOIO) {
+ put_page(page);
+ goto out;
+ }
page_cache_async_readahead(mapping,
ra, filp, page,
index, last_index - index);
@@ -2160,6 +2164,11 @@ page_not_up_to_date_locked:
}
readpage:
+ if (iocb->ki_flags & IOCB_NOIO) {
+ unlock_page(page);
+ put_page(page);
+ goto would_block;
+ }
/*
* A previous I/O error may have been due to temporary
* failures, eg. multipath errors.
@@ -2249,9 +2258,19 @@ EXPORT_SYMBOL_GPL(generic_file_buffered_read);
*
* This is the "read_iter()" routine for all filesystems
* that can use the page cache directly.
+ *
+ * The IOCB_NOWAIT flag in iocb->ki_flags indicates that -EAGAIN shall
+ * be returned when no data can be read without waiting for I/O requests
+ * to complete; it doesn't prevent readahead.
+ *
+ * The IOCB_NOIO flag in iocb->ki_flags indicates that no new I/O
+ * requests shall be made for the read or for readahead. When no data
+ * can be read, -EAGAIN shall be returned. When readahead would be
+ * triggered, a partial, possibly empty read shall be returned.
+ *
* Return:
* * number of bytes copied, even for partial reads
- * * negative error code if nothing was read
+ * * negative error code (or 0 if IOCB_NOIO) if nothing was read
*/
ssize_t
generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 57ece74e3aae..fab4485b9e52 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1593,7 +1593,7 @@ static struct address_space *_get_hugetlb_page_mapping(struct page *hpage)
/* Use first found vma */
pgoff_start = page_to_pgoff(hpage);
- pgoff_end = pgoff_start + hpage_nr_pages(hpage) - 1;
+ pgoff_end = pgoff_start + pages_per_huge_page(page_hstate(hpage)) - 1;
anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root,
pgoff_start, pgoff_end) {
struct vm_area_struct *vma = avc->vma;
diff --git a/mm/migrate.c b/mm/migrate.c
index f37729673558..40cd7016ae6f 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1161,21 +1161,10 @@ out:
}
/*
- * gcc 4.7 and 4.8 on arm get an ICEs when inlining unmap_and_move(). Work
- * around it.
- */
-#if defined(CONFIG_ARM) && \
- defined(GCC_VERSION) && GCC_VERSION < 40900 && GCC_VERSION >= 40700
-#define ICE_noinline noinline
-#else
-#define ICE_noinline
-#endif
-
-/*
* Obtain the lock on page, remove all ptes and migrate the page
* to the newly allocated page in newpage.
*/
-static ICE_noinline int unmap_and_move(new_page_t get_new_page,
+static int unmap_and_move(new_page_t get_new_page,
free_page_t put_new_page,
unsigned long private, struct page *page,
int force, enum migrate_mode mode,
diff --git a/mm/mremap.c b/mm/mremap.c
index 5dd572d57ca9..6b153dc05fe4 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -206,9 +206,28 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
/*
* The destination pmd shouldn't be established, free_pgtables()
- * should have release it.
+ * should have released it.
+ *
+ * However, there's a case during execve() where we use mremap
+ * to move the initial stack, and in that case the target area
+ * may overlap the source area (always moving down).
+ *
+ * If everything is PMD-aligned, that works fine, as moving
+ * each pmd down will clear the source pmd. But if we first
+ * have a few 4kB-only pages that get moved down, and then
+ * hit the "now the rest is PMD-aligned, let's do everything
+ * one pmd at a time", we will still have the old (now empty
+ * of any 4kB pages, but still there) PMD in the page table
+ * tree.
+ *
+ * Warn on it once - because we really should try to figure
+ * out how to do this better - but then say "I won't move
+ * this pmd".
+ *
+ * One alternative might be to just unmap the target pmd at
+ * this point, and verify that it really is empty. We'll see.
*/
- if (WARN_ON(!pmd_none(*new_pmd)))
+ if (WARN_ON_ONCE(!pmd_none(*new_pmd)))
return false;
/*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 48eb0f1410d4..e028b87ce294 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7832,7 +7832,7 @@ void setup_per_zone_wmarks(void)
* Initialise min_free_kbytes.
*
* For small machines we want it small (128k min). For large machines
- * we want it large (64MB max). But it is not linear, because network
+ * we want it large (256MB max). But it is not linear, because network
* bandwidth does not increase linearly with machine size. We use
*
* min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: