The quilt patch titled
Subject: mm: use folio_xor_flags_has_waiters() in folio_end_writeback()
has been removed from the -mm tree. Its filename was
mm-use-folio_xor_flags_has_waiters-in-folio_end_writeback.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: use folio_xor_flags_has_waiters() in folio_end_writeback()
Date: Wed, 4 Oct 2023 17:53:17 +0100
Match how folio_unlock() works by combining the test for PG_waiters with
the clearing of PG_writeback. This should have a small performance win,
and removes the last user of folio_wake().
Link: https://lkml.kernel.org/r/20231004165317.1061855-18-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Richard Henderson <richard.henderson@xxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 15 +++------------
mm/internal.h | 2 +-
mm/page-writeback.c | 9 ++++++---
3 files changed, 10 insertions(+), 16 deletions(-)
--- a/mm/filemap.c~mm-use-folio_xor_flags_has_waiters-in-folio_end_writeback
+++ a/mm/filemap.c
@@ -1175,13 +1175,6 @@ static void folio_wake_bit(struct folio
spin_unlock_irqrestore(&q->lock, flags);
}
-static void folio_wake(struct folio *folio, int bit)
-{
- if (!folio_test_waiters(folio))
- return;
- folio_wake_bit(folio, bit);
-}
-
/*
* A choice of three behaviors for folio_wait_bit_common():
*/
@@ -1618,13 +1611,11 @@ void folio_end_writeback(struct folio *f
* Writeback does not hold a folio reference of its own, relying
* on truncation to wait for the clearing of PG_writeback.
* But here we must make sure that the folio is not freed and
- * reused before the folio_wake().
+ * reused before the folio_wake_bit().
*/
folio_get(folio);
- __folio_end_writeback(folio);
-
- smp_mb__after_atomic();
- folio_wake(folio, PG_writeback);
+ if (__folio_end_writeback(folio))
+ folio_wake_bit(folio, PG_writeback);
acct_reclaim_writeback(folio);
folio_put(folio);
}
--- a/mm/internal.h~mm-use-folio_xor_flags_has_waiters-in-folio_end_writeback
+++ a/mm/internal.h
@@ -105,7 +105,7 @@ static inline void wake_throttle_isolate
vm_fault_t do_swap_page(struct vm_fault *vmf);
void folio_rotate_reclaimable(struct folio *folio);
-void __folio_end_writeback(struct folio *folio);
+bool __folio_end_writeback(struct folio *folio);
void deactivate_file_folio(struct folio *folio);
void folio_activate(struct folio *folio);
--- a/mm/page-writeback.c~mm-use-folio_xor_flags_has_waiters-in-folio_end_writeback
+++ a/mm/page-writeback.c
@@ -2940,10 +2940,11 @@ static void wb_inode_writeback_end(struc
spin_unlock_irqrestore(&wb->work_lock, flags);
}
-void __folio_end_writeback(struct folio *folio)
+bool __folio_end_writeback(struct folio *folio)
{
long nr = folio_nr_pages(folio);
struct address_space *mapping = folio_mapping(folio);
+ bool ret;
folio_memcg_lock(folio);
if (mapping && mapping_use_writeback_tags(mapping)) {
@@ -2952,7 +2953,7 @@ void __folio_end_writeback(struct folio
unsigned long flags;
xa_lock_irqsave(&mapping->i_pages, flags);
- folio_test_clear_writeback(folio);
+ ret = folio_xor_flags_has_waiters(folio, 1 << PG_writeback);
__xa_clear_mark(&mapping->i_pages, folio_index(folio),
PAGECACHE_TAG_WRITEBACK);
if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
@@ -2970,13 +2971,15 @@ void __folio_end_writeback(struct folio
xa_unlock_irqrestore(&mapping->i_pages, flags);
} else {
- folio_test_clear_writeback(folio);
+ ret = folio_xor_flags_has_waiters(folio, 1 << PG_writeback);
}
lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
node_stat_mod_folio(folio, NR_WRITTEN, nr);
folio_memcg_unlock(folio);
+
+ return ret;
}
bool __folio_start_writeback(struct folio *folio, bool keep_write)
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
buffer-make-folio_create_empty_buffers-return-a-buffer_head.patch
mpage-convert-map_buffer_to_folio-to-folio_create_empty_buffers.patch
ext4-convert-to-folio_create_empty_buffers.patch
buffer-add-get_nth_bh.patch
gfs2-convert-inode-unstuffing-to-use-a-folio.patch
gfs2-convert-gfs2_getbuf-to-folios.patch
gfs2-convert-gfs2_getjdatabuf-to-use-a-folio.patch
gfs2-convert-gfs2_write_buf_to_page-to-use-a-folio.patch
nilfs2-convert-nilfs_mdt_freeze_buffer-to-use-a-folio.patch
nilfs2-convert-nilfs_grab_buffer-to-use-a-folio.patch
nilfs2-convert-nilfs_copy_page-to-nilfs_copy_folio.patch
nilfs2-convert-nilfs_mdt_forget_block-to-use-a-folio.patch
nilfs2-convert-nilfs_mdt_get_frozen_buffer-to-use-a-folio.patch
nilfs2-remove-nilfs_page_get_nth_block.patch
nilfs2-convert-nilfs_lookup_dirty_data_buffers-to-use-folio_create_empty_buffers.patch
ntfs-convert-ntfs_read_block-to-use-a-folio.patch
ntfs-convert-ntfs_writepage-to-use-a-folio.patch
ntfs-convert-ntfs_prepare_pages_for_non_resident_write-to-folios.patch
ntfs3-convert-ntfs_zero_range-to-use-a-folio.patch
ocfs2-convert-ocfs2_map_page_blocks-to-use-a-folio.patch
reiserfs-convert-writepage-to-use-a-folio.patch
ufs-add-ufs_get_locked_folio-and-ufs_put_locked_folio.patch
ufs-use-ufs_get_locked_folio-in-ufs_alloc_lastblock.patch
ufs-convert-ufs_change_blocknr-to-use-folios.patch
ufs-remove-ufs_get_locked_page.patch
buffer-remove-folio_create_empty_buffers.patch
