diff options
| author | Marco Crivellari <marco.crivellari@suse.com> | 2025-09-16 10:29:06 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-09-19 16:15:07 +0200 |
| commit | 69635d7f4b344e6f5344bba3c3de92e4fb8b0d2a (patch) | |
| tree | a71e029d3da0a0ffac7b73031a508f810b37c59d /fs/ocfs2 | |
| parent | 4ef64db060619be040351e3960e151e5fef3f895 (diff) | |
fs: WQ_PERCPU added to alloc_workqueue users
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This patch adds a new WQ_PERCPU flag to all the fs subsystem users to
explicitly request the use of the per-CPU behavior. Both flags coexist
for one release cycle to allow callers to transition their calls.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit 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.
All existing users have been updated accordingly.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/20250916082906.77439-4-marco.crivellari@suse.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/dlm/dlmdomain.c | 3 | ||||
| -rw-r--r-- | fs/ocfs2/dlmfs/dlmfs.c | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c index 2018501b2249..2347a50f079b 100644 --- a/fs/ocfs2/dlm/dlmdomain.c +++ b/fs/ocfs2/dlm/dlmdomain.c @@ -1876,7 +1876,8 @@ static int dlm_join_domain(struct dlm_ctxt *dlm) dlm_debug_init(dlm); snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name); - dlm->dlm_worker = alloc_workqueue(wq_name, WQ_MEM_RECLAIM, 0); + dlm->dlm_worker = alloc_workqueue(wq_name, WQ_MEM_RECLAIM | WQ_PERCPU, + 0); if (!dlm->dlm_worker) { status = -ENOMEM; mlog_errno(status); diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c index 5130ec44e5e1..0b730535b2c8 100644 --- a/fs/ocfs2/dlmfs/dlmfs.c +++ b/fs/ocfs2/dlmfs/dlmfs.c @@ -595,7 +595,8 @@ static int __init init_dlmfs_fs(void) } cleanup_inode = 1; - user_dlm_worker = alloc_workqueue("user_dlm", WQ_MEM_RECLAIM, 0); + user_dlm_worker = alloc_workqueue("user_dlm", + WQ_MEM_RECLAIM | WQ_PERCPU, 0); if (!user_dlm_worker) { status = -ENOMEM; goto bail; |