If the dirty folio is not reclaimed in the shrink process, it do
not need to unmap, which can save shrinking time during traversaling
the dirty folio.
Signed-off-by: Zhiguo Jiang <justinjiang@xxxxxxxx>
---
mm/vmscan.c | 72 +++++++++++++++++++++++++++--------------------------
1 file changed, 37 insertions(+), 35 deletions(-)
mode change 100644 => 100755 mm/vmscan.c
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2cc0cb41fb32..cf555cdfcefc
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1261,6 +1261,43 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
enum ttu_flags flags = TTU_BATCH_FLUSH;
bool was_swapbacked = folio_test_swapbacked(folio);
+ if (folio_test_dirty(folio)) {
+ /*
+ * Only kswapd can writeback filesystem folios
+ * to avoid risk of stack overflow. But avoid
+ * injecting inefficient single-folio I/O into
+ * flusher writeback as much as possible: only
+ * write folios when we've encountered many
+ * dirty folios, and when we've already scanned
+ * the rest of the LRU for clean folios and see
+ * the same dirty folios again (with the reclaim
+ * flag set).
+ */
+ if (folio_is_file_lru(folio) &&
+ (!current_is_kswapd() ||
+ !folio_test_reclaim(folio) ||
+ !test_bit(PGDAT_DIRTY, &pgdat->flags))) {
+ /*
+ * Immediately reclaim when written back.
+ * Similar in principle to folio_deactivate()
+ * except we already have the folio isolated
+ * and know it's dirty
+ */
+ node_stat_mod_folio(folio, NR_VMSCAN_IMMEDIATE,
+ nr_pages);
+ folio_set_reclaim(folio);
+
+ goto activate_locked;
+ }
+
+ if (references == FOLIOREF_RECLAIM_CLEAN)
+ goto keep_locked;
+ if (!may_enter_fs(folio, sc->gfp_mask))
+ goto keep_locked;
+ if (!sc->may_writepage)
+ goto keep_locked;
+ }
+
if (folio_test_pmd_mappable(folio))
flags |= TTU_SPLIT_HUGE_PMD;
@@ -1286,41 +1323,6 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
mapping = folio_mapping(folio);
if (folio_test_dirty(folio)) {
- /*
- * Only kswapd can writeback filesystem folios
- * to avoid risk of stack overflow. But avoid
- * injecting inefficient single-folio I/O into
- * flusher writeback as much as possible: only
- * write folios when we've encountered many
- * dirty folios, and when we've already scanned
- * the rest of the LRU for clean folios and see
- * the same dirty folios again (with the reclaim
- * flag set).
- */
- if (folio_is_file_lru(folio) &&
- (!current_is_kswapd() ||
- !folio_test_reclaim(folio) ||
- !test_bit(PGDAT_DIRTY, &pgdat->flags))) {
- /*
- * Immediately reclaim when written back.
- * Similar in principle to folio_deactivate()
- * except we already have the folio isolated
- * and know it's dirty
- */
- node_stat_mod_folio(folio, NR_VMSCAN_IMMEDIATE,
- nr_pages);
- folio_set_reclaim(folio);
-
- goto activate_locked;
- }
-
- if (references == FOLIOREF_RECLAIM_CLEAN)
- goto keep_locked;
- if (!may_enter_fs(folio, sc->gfp_mask))
- goto keep_locked;
- if (!sc->may_writepage)
- goto keep_locked;
-
/*
* Folio is dirty. Flush the TLB if a writable entry
* potentially exists to avoid CPU writes after I/O
--
2.39.0
