github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-13 14:44:42 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

workqueue: use rcu_dereference_sched() in workqueue_congested()

Browse Source 
workqueue_congested() fetches the pwq out of wq->cpu_pwq with a plain
load, so sparse complains about the dropped __rcu:

  kernel/workqueue.c:6304:13: sparse: incorrect type in assignment (different address spaces) @@     expected struct pool_workqueue *pwq @@     got struct pool_workqueue [noderef] __rcu * @@

A pwq is released with kfree_rcu() and the read is protected by the
surrounding preempt_disable(), which is what
commit fd5081f4ef ("workqueue: Remove redundant rcu_read_lock/unlock() in
workqueue_congested()") relied on when it dropped the rcu_read_lock()
here.

Use the rcu_dereference_sched() helper to make that explicit.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202608120931.tvTzq1gD-lkp@intel.com/
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Breno Leitao 2026-08-12 09:03:18 -07:00 committed by Tejun Heo
parent a5bde5d8fd
commit 7aef540078
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/workqueue.c
View File

@ -6317,7 +6317,7 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq)
if (cpu == WORK_CPU_UNBOUND)
cpu = smp_processor_id();
pwq = *per_cpu_ptr(wq->cpu_pwq, cpu);
pwq = rcu_dereference_sched(*per_cpu_ptr(wq->cpu_pwq, cpu));
ret = !list_empty(&pwq->inactive_works);
preempt_enable();