mm: use folio_xor_flags_has_waiters() in folio_end_writeback()

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@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-10-04 17:53:17 +01:00 committed by Andrew Morton
parent 7d0795d098
commit 2580d55458
3 changed files with 10 additions and 16 deletions

View File

@ -1175,13 +1175,6 @@ static void folio_wake_bit(struct folio *folio, int bit_nr)
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 *folio)
* 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);
}

View File

@ -105,7 +105,7 @@ static inline void wake_throttle_isolated(pg_data_t *pgdat)
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);

View File

@ -2940,10 +2940,11 @@ static void wb_inode_writeback_end(struct bdi_writeback *wb)
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 *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 *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)