The patch titled
Subject: mm/thp: allow dropping THP from page cache
has been added to the -mm tree. Its filename is
mm-thp-allow-drop-thp-from-page-cache.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-thp-allow-drop-thp-from-page-cache.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-allow-drop-thp-from-page-cache.patch
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 and is updated
there every 3-4 working days
------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mm/thp: allow dropping THP from page cache
Once a THP is added to the page cache, it cannot be dropped via
/proc/sys/vm/drop_caches. Fix this issue with proper handling in
invalidate_mapping_pages().
Link: http://lkml.kernel.org/r/20191017164223.2762148-5-songliubraving@xxxxxx
Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Tested-by: Song Liu <songliubraving@xxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: William Kucharski <william.kucharski@xxxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/truncate.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/mm/truncate.c~mm-thp-allow-drop-thp-from-page-cache
+++ a/mm/truncate.c
@@ -592,6 +592,16 @@ unsigned long invalidate_mapping_pages(s
unlock_page(page);
continue;
}
+
+ /* Take a pin outside pagevec */
+ get_page(page);
+
+ /*
+ * Drop extra pins before trying to invalidate
+ * the huge page.
+ */
+ pagevec_remove_exceptionals(&pvec);
+ pagevec_release(&pvec);
}
ret = invalidate_inode_page(page);
@@ -602,6 +612,8 @@ unsigned long invalidate_mapping_pages(s
*/
if (!ret)
deactivate_file_page(page);
+ if (PageTransHuge(page))
+ put_page(page);
count += ret;
}
pagevec_remove_exceptionals(&pvec);
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
proc-meminfo-fix-output-alignment.patch
mm-thp-fix-node-page-state-in-split_huge_page_to_list.patch
mm-thp-allow-drop-thp-from-page-cache.patch
shmem-pin-the-file-in-shmem_fault-if-mmap_sem-is-dropped.patch
