diff mbox series

[02/48] fs/writeback: Convert inode_switch_wbs_work_fn to folios

Message ID 20211208042256.1923824-3-willy@infradead.org (mailing list archive)
State New
Headers show
Series Folios for 5.17 | expand

Commit Message

Matthew Wilcox (Oracle) Dec. 8, 2021, 4:22 a.m. UTC 
This gets the statistics correct by modifying the counters by the
number of pages in the folio instead of by 1.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/fs-writeback.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

Comments

Christoph Hellwig Dec. 23, 2021, 6:50 a.m. UTC | #1 
On Wed, Dec 08, 2021 at 04:22:10AM +0000, Matthew Wilcox (Oracle) wrote:
> This gets the statistics correct by modifying the counters by the
> number of pages in the folio instead of by 1.

We can't actually hit this for a multi-page folio yet, can we?
So this should be more of a prep patch?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Matthew Wilcox (Oracle) Dec. 23, 2021, 1:50 p.m. UTC | #2 
On Wed, Dec 22, 2021 at 10:50:20PM -0800, Christoph Hellwig wrote:
> On Wed, Dec 08, 2021 at 04:22:10AM +0000, Matthew Wilcox (Oracle) wrote:
> > This gets the statistics correct by modifying the counters by the
> > number of pages in the folio instead of by 1.
> 
> We can't actually hit this for a multi-page folio yet, can we?
> So this should be more of a prep patch?
> 
> Otherwise looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Right, even by the end of this series, we don't actually create large
folios.  I was hoping to get to that point, but there's still a reliance
on CONFIG_TRANSPARENT_HUGEPAGE that I need to get rid of.
diff mbox series

Patch

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 67f0e88eed01..4f680f848c8b 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -372,7 +372,7 @@  static bool inode_do_switch_wbs(struct inode *inode,
 {
 	struct address_space *mapping = inode->i_mapping;
 	XA_STATE(xas, &mapping->i_pages, 0);
-	struct page *page;
+	struct folio *folio;
 	bool switched = false;
 
 	spin_lock(&inode->i_lock);
@@ -389,21 +389,23 @@  static bool inode_do_switch_wbs(struct inode *inode,
 
 	/*
 	 * Count and transfer stats.  Note that PAGECACHE_TAG_DIRTY points
-	 * to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to
-	 * pages actually under writeback.
+	 * to possibly dirty folios while PAGECACHE_TAG_WRITEBACK points to
+	 * folios actually under writeback.
 	 */
-	xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_DIRTY) {
-		if (PageDirty(page)) {
-			dec_wb_stat(old_wb, WB_RECLAIMABLE);
-			inc_wb_stat(new_wb, WB_RECLAIMABLE);
+	xas_for_each_marked(&xas, folio, ULONG_MAX, PAGECACHE_TAG_DIRTY) {
+		if (folio_test_dirty(folio)) {
+			long nr = folio_nr_pages(folio);
+			wb_stat_mod(old_wb, WB_RECLAIMABLE, -nr);
+			wb_stat_mod(new_wb, WB_RECLAIMABLE, nr);
 		}
 	}
 
 	xas_set(&xas, 0);
-	xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) {
-		WARN_ON_ONCE(!PageWriteback(page));
-		dec_wb_stat(old_wb, WB_WRITEBACK);
-		inc_wb_stat(new_wb, WB_WRITEBACK);
+	xas_for_each_marked(&xas, folio, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) {
+		long nr = folio_nr_pages(folio);
+		WARN_ON_ONCE(!folio_test_writeback(folio));
+		wb_stat_mod(old_wb, WB_WRITEBACK, -nr);
+		wb_stat_mod(new_wb, WB_WRITEBACK, nr);
 	}
 
 	if (mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) {