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-rw-r--r--mm/vmscan.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index ce2ee8331414..92e56cadceae 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1153,13 +1153,18 @@ static unsigned long shrink_page_list(struct list_head *page_list,
if (PageDirty(page)) {
/*
- * Only kswapd can writeback filesystem pages to
- * avoid risk of stack overflow but only writeback
- * if many dirty pages have been encountered.
+ * Only kswapd can writeback filesystem pages
+ * to avoid risk of stack overflow. But avoid
+ * injecting inefficient single-page IO into
+ * flusher writeback as much as possible: only
+ * write pages when we've encountered many
+ * dirty pages, and when we've already scanned
+ * the rest of the LRU for clean pages and see
+ * the same dirty pages again (PageReclaim).
*/
if (page_is_file_cache(page) &&
- (!current_is_kswapd() ||
- !test_bit(PGDAT_DIRTY, &pgdat->flags))) {
+ (!current_is_kswapd() || !PageReclaim(page) ||
+ !test_bit(PGDAT_DIRTY, &pgdat->flags))) {
/*
* Immediately reclaim when written back.
* Similar in principal to deactivate_page()