mm: add WQ_PERCPU to alloc_workqueue users

This continues the effort to refactor workqueue APIs, which began with the
introduction of new workqueues and a new alloc_workqueue flag in:

   commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
   commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

The refactoring is going to alter the default behavior of
alloc_workqueue() to be unbound by default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn't explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.  For more details see the Link tag below.

In order to keep alloc_workqueue() behavior identical, explicitly request
WQ_PERCPU.

[akpm@linux-foundation.org: fix mm/slub.c]
[akpm@linux-foundation.org: fix kmem_cache_init_late() properly, per Sebastian]
Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Link: https://lkml.kernel.org/r/20260113114630.152942-4-marco.crivellari@suse.com
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lai jiangshan <jiangshanlai@gmail.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 69361742893adfdd08cfffcc31753e77941da3d9..e319bd5e8b75c863d2d1e62ca68cd1ffbcdb083f 100644 (file)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -974,7 +974,7 @@ static int __init cgwb_init(void)
         * system_percpu_wq.  Put them in a separate wq and limit concurrency.
         * There's no point in executing many of these in parallel.
         */
-       cgwb_release_wq = alloc_workqueue("cgwb_release", 0, 1);
+       cgwb_release_wq = alloc_workqueue("cgwb_release", WQ_PERCPU, 1);
        if (!cgwb_release_wq)
                return -ENOMEM;
 

diff --git a/mm/slub.c b/mm/slub.c
index 861592ac54257b9d148ff921e6d8f62aced607b3..409d16695c8bc4b1ecb2e5f619b3a5aca8bd60c6 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -8542,7 +8542,8 @@ void __init kmem_cache_init(void)
 
 void __init kmem_cache_init_late(void)
 {
-       flushwq = alloc_workqueue("slub_flushwq", WQ_MEM_RECLAIM, 0);
+       flushwq = alloc_workqueue("slub_flushwq", WQ_MEM_RECLAIM | WQ_PERCPU,
+                                 0);
        WARN_ON(!flushwq);
 }
 

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 23e176e1d09d77152d7b0a3db703ca3531df2fa6..99270713e0c13635225ab4ce22dea9485cbab48d 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -2259,7 +2259,8 @@ void __init init_mm_internals(void)
 {
        int ret __maybe_unused;
 
-       mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0);
+       mm_percpu_wq = alloc_workqueue("mm_percpu_wq",
+                                      WQ_MEM_RECLAIM | WQ_PERCPU, 0);
 
 #ifdef CONFIG_SMP
        ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",