Add a folio flag that file IO can use to indicate that the cached IO
being done should be dropped from the page cache upon completion.
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
include/linux/page-flags.h | 5 +++++
include/trace/events/mmflags.h | 3 ++-
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index cf46ac720802..16607f02abd0 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -110,6 +110,7 @@ enum pageflags {
PG_reclaim, /* To be reclaimed asap */
PG_swapbacked, /* Page is backed by RAM/swap */
PG_unevictable, /* Page is "unevictable" */
+ PG_dropbehind, /* drop pages on IO completion */
#ifdef CONFIG_MMU
PG_mlocked, /* Page is vma mlocked */
#endif
@@ -562,6 +563,10 @@ PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL)
FOLIO_FLAG(readahead, FOLIO_HEAD_PAGE)
FOLIO_TEST_CLEAR_FLAG(readahead, FOLIO_HEAD_PAGE)
+FOLIO_FLAG(dropbehind, FOLIO_HEAD_PAGE)
+ FOLIO_TEST_CLEAR_FLAG(dropbehind, FOLIO_HEAD_PAGE)
+ __FOLIO_SET_FLAG(dropbehind, FOLIO_HEAD_PAGE)
+
#ifdef CONFIG_HIGHMEM
/*
* Must use a macro here due to header dependency issues. page_zone() is not
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index bb8a59c6caa2..3bc8656c8359 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -116,7 +116,8 @@
DEF_PAGEFLAG_NAME(head), \
DEF_PAGEFLAG_NAME(reclaim), \
DEF_PAGEFLAG_NAME(swapbacked), \
- DEF_PAGEFLAG_NAME(unevictable) \
+ DEF_PAGEFLAG_NAME(unevictable), \
+ DEF_PAGEFLAG_NAME(dropbehind) \
IF_HAVE_PG_MLOCK(mlocked) \
IF_HAVE_PG_HWPOISON(hwpoison) \
IF_HAVE_PG_IDLE(idle) \
--
2.45.2
