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[172.10.233.147]) by smtp.gmail.com with ESMTPSA id 00721157ae682-84caabb9e88sm34369867b3.29.2026.08.24.07.47.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Aug 2026 07:47:24 -0700 (PDT) Date: Mon, 24 Aug 2026 07:47:20 -0700 (PDT) From: Hugh Dickins To: Andrew Morton cc: Ackerley Tng , Alexander Viro , Baolin Wang , Barry Song , Binbin Wu , Christian Brauner , Christoph Hellwig , Christoph Lameter , Claudio Imbrenda , David Hildenbrand , JP Kobryn , Jan Kara , Jens Axboe , Johannes Weiner , Kairui Song , Kiryl Shutsemau , Lance Yang , Leonardo Bras , Lorenzo Stoakes , Marcelo Tosatti , Matthew Wilcox , Mel Gorman , Miaohe Lin , Michal Hocko , Minchan Kim , Muchun Song , Oscar Salvador , Peter Zijlstra , Qi Zheng , Rik van Riel , Sebastian Andrzej Siewior , Shakeel Butt , Suren Baghdasaryan , Vlastimil Babka , Yang Shi , Yu Zhao , Zach O'Keefe , Zi Yan , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 23/25] fs,mm/fbatch: use invalidate_bh_lrus() not invalidate_bh_lrus_cpu() In-Reply-To: <14a16945-529b-8bc0-ab38-3ea97e54e223@google.com> Message-ID: References: <14a16945-529b-8bc0-ab38-3ea97e54e223@google.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Whilst there can be a case for including an invalidate_bh_lrus_cpu() in lru_add_drain_all()'s workqueued visits to remote CPUs, wouldn't it now be a preferable cleanup to remove that alternative, and stick with the smp_call_function_many_cond()-based invalidate_bh_lrus() throughout? And fix the UP lru_add_drain_all() to include an invalidate_bh_lrus(), which went missing when 5.15 commit 243418e3925d ("mm: fs: invalidate bh_lrus for only cold path") took that out of lru_add_drain(). Signed-off-by: Hugh Dickins --- fs/buffer.c | 16 +--------------- include/linux/buffer_head.h | 4 ---- mm/folio.c | 25 ++++++------------------- 3 files changed, 7 insertions(+), 38 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index ed966fa73b1b..7d114e5b9c62 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1427,7 +1427,7 @@ static void invalidate_bh_lru(void *arg) put_cpu_var(bh_lrus); } -bool has_bh_in_lru(int cpu, void *dummy) +static bool has_bh_in_lru(int cpu, void *dummy) { struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu); int i; @@ -1446,20 +1446,6 @@ void invalidate_bh_lrus(void) } EXPORT_SYMBOL_GPL(invalidate_bh_lrus); -/* - * It's called from workqueue context so we need a bh_lru_lock to close - * the race with preemption/irq. - */ -void invalidate_bh_lrus_cpu(void) -{ - struct bh_lru *b; - - bh_lru_lock(); - b = this_cpu_ptr(&bh_lrus); - __invalidate_bh_lrus(b); - bh_lru_unlock(); -} - void folio_set_bh(struct buffer_head *bh, struct folio *folio, unsigned long offset) { diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index fd2c7115c054..f19f9e80be8f 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -518,8 +518,6 @@ bool mmb_has_buffers(struct mapping_metadata_bhs *mmb); void mmb_invalidate(struct mapping_metadata_bhs *mmb); int mmb_sync(struct mapping_metadata_bhs *mmb); void invalidate_bh_lrus(void); -void invalidate_bh_lrus_cpu(void); -bool has_bh_in_lru(int cpu, void *dummy); extern int buffer_heads_over_limit; #else /* CONFIG_BUFFER_HEAD */ @@ -528,8 +526,6 @@ static inline void buffer_init(void) {} static inline bool try_to_free_buffers(struct folio *folio) { return true; } static inline int mmb_sync(struct mapping_metadata_bhs *mmb) { return 0; } static inline void invalidate_bh_lrus(void) {} -static inline void invalidate_bh_lrus_cpu(void) {} -static inline bool has_bh_in_lru(int cpu, void *dummy) { return false; } #define buffer_heads_over_limit 0 #endif /* CONFIG_BUFFER_HEAD */ diff --git a/mm/folio.c b/mm/folio.c index 782b8245d213..3212c7a58623 100644 --- a/mm/folio.c +++ b/mm/folio.c @@ -748,21 +748,6 @@ void lru_add_drain(void) mlock_drain_local(); } -/* - * It's called from per-cpu workqueue context in SMP case so - * lru_add_drain_cpu and invalidate_bh_lrus_cpu should run on - * the same cpu. It shouldn't be a problem in !SMP case since - * the core is only one and the locks will disable preemption. - */ -static void lru_add_and_bh_lrus_drain(void) -{ - local_lock(&cpu_fbatches.lock); - lru_add_drain_cpu(smp_processor_id()); - local_unlock(&cpu_fbatches.lock); - invalidate_bh_lrus_cpu(); - mlock_drain_local(); -} - void lru_add_drain_cpu_zone(struct zone *zone) { local_lock(&cpu_fbatches.lock); @@ -778,7 +763,7 @@ static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); static void lru_add_drain_per_cpu(struct work_struct *dummy) { - lru_add_and_bh_lrus_drain(); + lru_add_drain(); } static bool cpu_needs_drain(unsigned int cpu) @@ -791,8 +776,7 @@ static bool cpu_needs_drain(unsigned int cpu) folio_batch_count(&fbatches->lru_move_tail) || folio_batch_count(&fbatches->lru_deactivate_file) || folio_batch_count(&fbatches->lru_deactivate) || - need_mlock_drain(cpu)) || - has_bh_in_lru(cpu, NULL); + need_mlock_drain(cpu)); } /* @@ -891,6 +875,8 @@ static inline void __lru_add_drain_all(bool force_all_cpus) } } + invalidate_bh_lrus(); + for_each_cpu(cpu, &has_work) flush_work(&per_cpu(lru_add_drain_work, cpu)); @@ -906,6 +892,7 @@ void lru_add_drain_all(void) void lru_add_drain_all(void) { lru_add_drain(); + invalidate_bh_lrus(); } #endif /* CONFIG_SMP */ @@ -939,7 +926,7 @@ void lru_cache_disable(void) #ifdef CONFIG_SMP __lru_add_drain_all(true); #else - lru_add_and_bh_lrus_drain(); + lru_add_drain_all(); #endif } -- 2.51.0