git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From aac8a59537dfc704ff344f1aacfd143c089ee20f Mon Sep 17 00:00:00 2001
   2 From: Tejun Heo <tj@kernel.org>
   3 Date: Mon, 5 Feb 2024 15:43:41 -1000
   4 Subject: Revert "workqueue: Override implicit ordered attribute in workqueue_apply_unbound_cpumask()"
   5
   6 From: Tejun Heo <tj@kernel.org>
   7
   8 commit aac8a59537dfc704ff344f1aacfd143c089ee20f upstream.
   9
  10 This reverts commit ca10d851b9ad0338c19e8e3089e24d565ebfffd7.
  11
  12 The commit allowed workqueue_apply_unbound_cpumask() to clear __WQ_ORDERED
  13 on now removed implicitly ordered workqueues. This was incorrect in that
  14 system-wide config change shouldn't break ordering properties of all
  15 workqueues. The reason why apply_workqueue_attrs() path was allowed to do so
  16 was because it was targeting the specific workqueue - either the workqueue
  17 had WQ_SYSFS set or the workqueue user specifically tried to change
  18 max_active, both of which indicate that the workqueue doesn't need to be
  19 ordered.
  20
  21 The implicitly ordered workqueue promotion was removed by the previous
  22 commit 3bc1e711c26b ("workqueue: Don't implicitly make UNBOUND workqueues w/
  23 @max_active==1 ordered"). However, it didn't update this path and broke
  24 build. Let's revert the commit which was incorrect in the first place which
  25 also fixes build.
  26
  27 Signed-off-by: Tejun Heo <tj@kernel.org>
  28 Fixes: 3bc1e711c26b ("workqueue: Don't implicitly make UNBOUND workqueues w/ @max_active==1 ordered")
  29 Fixes: ca10d851b9ad ("workqueue: Override implicit ordered attribute in workqueue_apply_unbound_cpumask()")
  30 Cc: stable@vger.kernel.org # v6.6+
  31 Signed-off-by: Tejun Heo <tj@kernel.org>
  32 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  33 ---
  34  kernel/workqueue.c |    8 ++------
  35  1 file changed, 2 insertions(+), 6 deletions(-)
  36
  37 --- a/kernel/workqueue.c
  38 +++ b/kernel/workqueue.c
  39 @@ -5793,13 +5793,9 @@ static int workqueue_apply_unbound_cpuma
  40         list_for_each_entry(wq, &workqueues, list) {
  41                 if (!(wq->flags & WQ_UNBOUND))
  42                         continue;
  43 -
  44                 /* creating multiple pwqs breaks ordering guarantee */
  45 -               if (!list_empty(&wq->pwqs)) {
  46 -                       if (wq->flags & __WQ_ORDERED_EXPLICIT)
  47 -                               continue;
  48 -                       wq->flags &= ~__WQ_ORDERED;
  49 -               }
  50 +               if (wq->flags & __WQ_ORDERED)
  51 +                       continue;
  52
  53                 ctx = apply_wqattrs_prepare(wq, wq->unbound_attrs, unbound_cpumask);
  54                 if (IS_ERR(ctx)) {