+ mm-handle-thp-in-swap_page_fs-count_vm_events.patch added to mm-unstable branch

+ mm-handle-thp-in-swap_page_fs-count_vm_events.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: MM: handle THP in swap_*page_fs() - count_vm_events()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-handle-thp-in-swap_page_fs-count_vm_events.patch

This patch should soon appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: "NeilBrown" <neilb@suse.de>
Subject: MM: handle THP in swap_*page_fs() - count_vm_events()

We need to use count_swpout_vm_event() for sio_write_complete() to get
correct counting.

Note that THP swap in (if it ever happens) is current accounted 1 for each
page, whether HUGE or normal.  This is different from swap-out accounting.

This patch should be squashed into
    MM: handle THP in swap_*page_fs()

Link: https://lkml.kernel.org/r/165146948934.24404.5909750610552745025@noble.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_io.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/mm/page_io.c~mm-handle-thp-in-swap_page_fs-count_vm_events
+++ a/mm/page_io.c
@@ -280,8 +280,10 @@ static void sio_write_complete(struct ki
 			set_page_dirty(page);
 			ClearPageReclaim(page);
 		}
-	} else
-		count_vm_events(PSWPOUT, sio->pages);
+	} else {
+		for (p = 0; p < sio->pages; p++)
+			count_swpout_vm_event(sio->bvec[p].bv_page);
+	}
 
 	for (p = 0; p < sio->pages; p++)
 		end_page_writeback(sio->bvec[p].bv_page);
_

Patches currently in -mm which might be from neilb@suse.de are

mm-create-new-mm-swaph-header-file.patch
mm-drop-swap_dirty_folio.patch
mm-move-responsibility-for-setting-swp_fs_ops-to-swap_activate.patch
mm-reclaim-mustnt-enter-fs-for-swp_fs_ops-swap-space.patch
mm-introduce-swap_rw-and-use-it-for-reads-from-swp_fs_ops-swap-space.patch
nfs-rename-nfs_direct_io-and-use-as-swap_rw.patch
mm-perform-async-writes-to-swp_fs_ops-swap-space-using-swap_rw.patch
doc-update-documentation-for-swap_activate-and-swap_rw.patch
mm-submit-multipage-reads-for-swp_fs_ops-swap-space.patch
mm-submit-multipage-write-for-swp_fs_ops-swap-space.patch
mm-handle-thp-in-swap_page_fs.patch
mm-handle-thp-in-swap_page_fs-count_vm_events.patch
vfs-add-fmode_can_odirect-file-flag.patch
mm-discard-__gfp_atomic.patch