To merge all kinds of rmap traverse functions, try_to_unmap(),
try_to_munlock(), page_referenced() and page_mkclean(), we need to
extract common parts and separate out non-common parts.
Nonlinear handling is handled just in try_to_unmap_file() and other
rmap traverse functions doesn't care of it. Therfore it is better
to factor nonlinear handling out of try_to_unmap_file() in order to
merge all kinds of rmap traverse functions easily.
Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
diff --git a/mm/rmap.c b/mm/rmap.c
index 20c1a0d..a387c44 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1422,6 +1422,79 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
return ret;
}
+static int try_to_unmap_nonlinear(struct page *page,
+ struct address_space *mapping, struct vm_area_struct *vma)
+{
+ int ret = SWAP_AGAIN;
+ unsigned long cursor;
+ unsigned long max_nl_cursor = 0;
+ unsigned long max_nl_size = 0;
+ unsigned int mapcount;
+
+ list_for_each_entry(vma,
+ &mapping->i_mmap_nonlinear, shared.nonlinear) {
+
+ cursor = (unsigned long) vma->vm_private_data;
+ if (cursor > max_nl_cursor)
+ max_nl_cursor = cursor;
+ cursor = vma->vm_end - vma->vm_start;
+ if (cursor > max_nl_size)
+ max_nl_size = cursor;
+ }
+
+ if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */
+ return SWAP_FAIL;
+ }
+
+ /*
+ * We don't try to search for this page in the nonlinear vmas,
+ * and page_referenced wouldn't have found it anyway. Instead
+ * just walk the nonlinear vmas trying to age and unmap some.
+ * The mapcount of the page we came in with is irrelevant,
+ * but even so use it as a guide to how hard we should try?
+ */
+ mapcount = page_mapcount(page);
+ if (!mapcount)
+ return ret;
+
+ cond_resched();
+
+ max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
+ if (max_nl_cursor == 0)
+ max_nl_cursor = CLUSTER_SIZE;
+
+ do {
+ list_for_each_entry(vma,
+ &mapping->i_mmap_nonlinear, shared.nonlinear) {
+
+ cursor = (unsigned long) vma->vm_private_data;
+ while (cursor < max_nl_cursor &&
+ cursor < vma->vm_end - vma->vm_start) {
+ if (try_to_unmap_cluster(cursor, &mapcount,
+ vma, page) == SWAP_MLOCK)
+ ret = SWAP_MLOCK;
+ cursor += CLUSTER_SIZE;
+ vma->vm_private_data = (void *) cursor;
+ if ((int)mapcount <= 0)
+ return ret;
+ }
+ vma->vm_private_data = (void *) max_nl_cursor;
+ }
+ cond_resched();
+ max_nl_cursor += CLUSTER_SIZE;
+ } while (max_nl_cursor <= max_nl_size);
+
+ /*
+ * Don't loop forever (perhaps all the remaining pages are
+ * in locked vmas). Reset cursor on all unreserved nonlinear
+ * vmas, now forgetting on which ones it had fallen behind.
+ */
+ list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
+ vma->vm_private_data = NULL;
+
+ return ret;
+}
+
bool is_vma_temporary_stack(struct vm_area_struct *vma)
{
int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
@@ -1511,10 +1584,6 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
pgoff_t pgoff = page->index << compound_order(page);
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
- unsigned long cursor;
- unsigned long max_nl_cursor = 0;
- unsigned long max_nl_size = 0;
- unsigned int mapcount;
mutex_lock(&mapping->i_mmap_mutex);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
@@ -1535,64 +1604,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
if (TTU_ACTION(flags) == TTU_MUNLOCK)
goto out;
- list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
- shared.nonlinear) {
- cursor = (unsigned long) vma->vm_private_data;
- if (cursor > max_nl_cursor)
- max_nl_cursor = cursor;
- cursor = vma->vm_end - vma->vm_start;
- if (cursor > max_nl_size)
- max_nl_size = cursor;
- }
-
- if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */
- ret = SWAP_FAIL;
- goto out;
- }
-
- /*
- * We don't try to search for this page in the nonlinear vmas,
- * and page_referenced wouldn't have found it anyway. Instead
- * just walk the nonlinear vmas trying to age and unmap some.
- * The mapcount of the page we came in with is irrelevant,
- * but even so use it as a guide to how hard we should try?
- */
- mapcount = page_mapcount(page);
- if (!mapcount)
- goto out;
- cond_resched();
-
- max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
- if (max_nl_cursor == 0)
- max_nl_cursor = CLUSTER_SIZE;
-
- do {
- list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
- shared.nonlinear) {
- cursor = (unsigned long) vma->vm_private_data;
- while ( cursor < max_nl_cursor &&
- cursor < vma->vm_end - vma->vm_start) {
- if (try_to_unmap_cluster(cursor, &mapcount,
- vma, page) == SWAP_MLOCK)
- ret = SWAP_MLOCK;
- cursor += CLUSTER_SIZE;
- vma->vm_private_data = (void *) cursor;
- if ((int)mapcount <= 0)
- goto out;
- }
- vma->vm_private_data = (void *) max_nl_cursor;
- }
- cond_resched();
- max_nl_cursor += CLUSTER_SIZE;
- } while (max_nl_cursor <= max_nl_size);
-
- /*
- * Don't loop forever (perhaps all the remaining pages are
- * in locked vmas). Reset cursor on all unreserved nonlinear
- * vmas, now forgetting on which ones it had fallen behind.
- */
- list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
- vma->vm_private_data = NULL;
+ ret = try_to_unmap_nonlinear(page, mapping, vma);
out:
mutex_unlock(&mapping->i_mmap_mutex);
return ret;
--
1.7.9.5
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