The patch titled
Subject: writeback: move the folio_prepare_writeback loop out of write_cache_pages()
has been added to the -mm mm-unstable branch. Its filename is
writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: writeback: move the folio_prepare_writeback loop out of write_cache_pages()
Date: Thu, 15 Feb 2024 07:36:47 +0100
Move the loop for should-we-write-this-folio to writeback_get_folio.
[hch@xxxxxx: fold loop into existing helper instead of a separate one per Jan]
Link: https://lkml.kernel.org/r/20240215063649.2164017-13-hch@xxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Acked-by: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
--- a/mm/page-writeback.c~writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages
+++ a/mm/page-writeback.c
@@ -2411,6 +2411,7 @@ static struct folio *writeback_get_folio
{
struct folio *folio;
+retry:
folio = folio_batch_next(&wbc->fbatch);
if (!folio) {
folio_batch_release(&wbc->fbatch);
@@ -2418,8 +2419,17 @@ static struct folio *writeback_get_folio
filemap_get_folios_tag(mapping, &wbc->index, wbc_end(wbc),
wbc_to_tag(wbc), &wbc->fbatch);
folio = folio_batch_next(&wbc->fbatch);
+ if (!folio)
+ return NULL;
+ }
+
+ folio_lock(folio);
+ if (unlikely(!folio_prepare_writeback(mapping, wbc, folio))) {
+ folio_unlock(folio);
+ goto retry;
}
+ trace_wbc_writepage(wbc, inode_to_bdi(mapping->host));
return folio;
}
@@ -2480,14 +2490,6 @@ int write_cache_pages(struct address_spa
if (!folio)
break;
- folio_lock(folio);
- if (!folio_prepare_writeback(mapping, wbc, folio)) {
- folio_unlock(folio);
- continue;
- }
-
- trace_wbc_writepage(wbc, inode_to_bdi(mapping->host));
-
error = writepage(folio, wbc, data);
wbc->nr_to_write -= folio_nr_pages(folio);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
memcg-convert-mem_cgroup_move_charge_pte_range-to-use-a-folio.patch
memcg-return-the-folio-in-union-mc_target.patch
memcg-use-a-folio-in-get_mctgt_type.patch
memcg-use-a-folio-in-get_mctgt_type_thp.patch
mm-add-pfn_swap_entry_folio.patch
proc-use-pfn_swap_entry_folio-where-obvious.patch
mprotect-use-pfn_swap_entry_folio.patch
highmem-add-kernel-doc-for-memcpy__folio.patch
rmap-replace-two-calls-to-compound_order-with-folio_order.patch
writeback-remove-a-duplicate-prototype-for-tag_pages_for_writeback.patch
writeback-factor-folio_prepare_writeback-out-of-write_cache_pages.patch
writeback-factor-writeback_get_batch-out-of-write_cache_pages.patch
writeback-simplify-the-loops-in-write_cache_pages.patch
pagevec-add-ability-to-iterate-a-queue.patch
writeback-use-the-folio_batch-queue-iterator.patch
writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages.patch
writeback-remove-a-use-of-write_cache_pages-from-do_writepages.patch
bounds-support-non-power-of-two-config_nr_cpus.patch
