When a task in memcg readaheads file pages, page_cache_ra_unbounded()
will try to readahead nr_to_read pages. Even if the new allocated page
fails to charge, page_cache_ra_unbounded() still tries to readahead
next page. This leads to too much memory reclaim.
Stop readahead if mem_cgroup_charge() fails, i.e. add_to_page_cache_lru()
returns -ENOMEM.
Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
Signed-off-by: Jinjiang Tu <tujinjiang@xxxxxxxxxx>
---
mm/readahead.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/readahead.c b/mm/readahead.c
index 23620c57c1225..cc4abb67eb223 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -228,6 +228,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl,
*/
for (i = 0; i < nr_to_read; i++) {
struct folio *folio = xa_load(&mapping->i_pages, index + i);
+ int ret;
if (folio && !xa_is_value(folio)) {
/*
@@ -247,9 +248,12 @@ void page_cache_ra_unbounded(struct readahead_control *ractl,
folio = filemap_alloc_folio(gfp_mask, 0);
if (!folio)
break;
- if (filemap_add_folio(mapping, folio, index + i,
- gfp_mask) < 0) {
+
+ ret = filemap_add_folio(mapping, folio, index + i, gfp_mask);
+ if (ret < 0) {
folio_put(folio);
+ if (ret == -ENOMEM)
+ break;
read_pages(ractl);
ractl->_index++;
i = ractl->_index + ractl->_nr_pages - index - 1;
--
2.25.1
