diff mbox series

[03/15] mm: add PG_uncached page flag

Message ID 20241110152906.1747545-4-axboe@kernel.dk (mailing list archive)
State New
Headers show
Series Uncached buffered IO | expand

Commit Message

Jens Axboe Nov. 10, 2024, 3:27 p.m. UTC 
Add a page flag that file IO can use to indicate that the IO being done
is uncached, as in it should not persist in the page cache after the IO
has been completed.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/page-flags.h     | 5 +++++
 include/trace/events/mmflags.h | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index cc839e4365c1..3c4003495929 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_uncached,		/* uncached read/write IO */
 #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(uncached, FOLIO_HEAD_PAGE)
+	FOLIO_TEST_CLEAR_FLAG(uncached, FOLIO_HEAD_PAGE)
+	__FOLIO_SET_FLAG(uncached, 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..b60057284102 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(uncached)					\
 IF_HAVE_PG_MLOCK(mlocked)						\
 IF_HAVE_PG_HWPOISON(hwpoison)						\
 IF_HAVE_PG_IDLE(idle)							\