lkml.org 
[lkml]   [2020]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 01/12] mm: Make pagecache tagged lookups return only head pages
Date
Pagecache tags are used for dirty page writeback.  Since dirtiness is
tracked on a per-THP basis, we only want to return the head page rather
than each subpage of a tagged page. All the filesystems which use huge
pages today are in-memory, so there are no tagged huge pages today.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
mm/filemap.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index f5fda3038782..7d8cf1a25628 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1968,7 +1968,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
EXPORT_SYMBOL(find_get_pages_contig);

/**
- * find_get_pages_range_tag - find and return pages in given range matching @tag
+ * find_get_pages_range_tag - Find and return head pages matching @tag.
* @mapping: the address_space to search
* @index: the starting page index
* @end: The final page index (inclusive)
@@ -1976,8 +1976,8 @@ EXPORT_SYMBOL(find_get_pages_contig);
* @nr_pages: the maximum number of pages
* @pages: where the resulting pages are placed
*
- * Like find_get_pages, except we only return pages which are tagged with
- * @tag. We update @index to index the next page for the traversal.
+ * Like find_get_pages(), except we only return head pages which are tagged
+ * with @tag. We update @index to index the next page for the traversal.
*
* Return: the number of pages which were found.
*/
@@ -2011,9 +2011,9 @@ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
if (unlikely(page != xas_reload(&xas)))
goto put_page;

- pages[ret] = find_subpage(page, xas.xa_index);
+ pages[ret] = page;
if (++ret == nr_pages) {
- *index = xas.xa_index + 1;
+ *index = page->index + thp_nr_pages(page);
goto out;
}
continue;
--
2.28.0
\
 
 \ /
  Last update: 2020-09-14 15:12    [W:0.202 / U:1.740 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site