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Revert "workqueue: RCU protect wq->dfl_pwq and implement accessors for it"
This reverts commit3fb5dbc8bb
which is commit9f66cff212
upstream. The workqueue patches backported to 6.8.y caused some reported regressions, so revert them for now. Reported-by: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Tejun Heo <tj@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Audra Mitchell <audra@redhat.com> Link: https://lore.kernel.org/all/ce4c2f67-c298-48a0-87a3-f933d646c73b@leemhuis.info/ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
f961f3587a
commit
9459d4af24
1 changed files with 24 additions and 40 deletions
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@ -304,7 +304,7 @@ struct workqueue_struct {
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int saved_max_active; /* WQ: saved max_active */
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struct workqueue_attrs *unbound_attrs; /* PW: only for unbound wqs */
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struct pool_workqueue __rcu *dfl_pwq; /* PW: only for unbound wqs */
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struct pool_workqueue *dfl_pwq; /* PW: only for unbound wqs */
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#ifdef CONFIG_SYSFS
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struct wq_device *wq_dev; /* I: for sysfs interface */
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@ -635,23 +635,6 @@ static int worker_pool_assign_id(struct worker_pool *pool)
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return ret;
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}
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static struct pool_workqueue __rcu **
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unbound_pwq_slot(struct workqueue_struct *wq, int cpu)
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{
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if (cpu >= 0)
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return per_cpu_ptr(wq->cpu_pwq, cpu);
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else
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return &wq->dfl_pwq;
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}
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/* @cpu < 0 for dfl_pwq */
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static struct pool_workqueue *unbound_pwq(struct workqueue_struct *wq, int cpu)
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{
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return rcu_dereference_check(*unbound_pwq_slot(wq, cpu),
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lockdep_is_held(&wq_pool_mutex) ||
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lockdep_is_held(&wq->mutex));
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}
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static unsigned int work_color_to_flags(int color)
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{
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return color << WORK_STRUCT_COLOR_SHIFT;
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@ -4341,11 +4324,10 @@ static void wq_calc_pod_cpumask(struct workqueue_attrs *attrs, int cpu,
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"possible intersect\n");
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}
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/* install @pwq into @wq and return the old pwq, @cpu < 0 for dfl_pwq */
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/* install @pwq into @wq's cpu_pwq and return the old pwq */
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static struct pool_workqueue *install_unbound_pwq(struct workqueue_struct *wq,
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int cpu, struct pool_workqueue *pwq)
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{
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struct pool_workqueue __rcu **slot = unbound_pwq_slot(wq, cpu);
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struct pool_workqueue *old_pwq;
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lockdep_assert_held(&wq_pool_mutex);
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@ -4354,8 +4336,8 @@ static struct pool_workqueue *install_unbound_pwq(struct workqueue_struct *wq,
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/* link_pwq() can handle duplicate calls */
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link_pwq(pwq);
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old_pwq = rcu_access_pointer(*slot);
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rcu_assign_pointer(*slot, pwq);
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old_pwq = rcu_access_pointer(*per_cpu_ptr(wq->cpu_pwq, cpu));
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rcu_assign_pointer(*per_cpu_ptr(wq->cpu_pwq, cpu), pwq);
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return old_pwq;
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}
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@ -4455,11 +4437,14 @@ static void apply_wqattrs_commit(struct apply_wqattrs_ctx *ctx)
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copy_workqueue_attrs(ctx->wq->unbound_attrs, ctx->attrs);
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/* save the previous pwqs and install the new ones */
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/* save the previous pwq and install the new one */
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for_each_possible_cpu(cpu)
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ctx->pwq_tbl[cpu] = install_unbound_pwq(ctx->wq, cpu,
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ctx->pwq_tbl[cpu]);
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ctx->dfl_pwq = install_unbound_pwq(ctx->wq, -1, ctx->dfl_pwq);
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/* @dfl_pwq might not have been used, ensure it's linked */
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link_pwq(ctx->dfl_pwq);
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swap(ctx->wq->dfl_pwq, ctx->dfl_pwq);
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mutex_unlock(&ctx->wq->mutex);
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}
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@ -4569,7 +4554,9 @@ static void wq_update_pod(struct workqueue_struct *wq, int cpu,
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/* nothing to do if the target cpumask matches the current pwq */
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wq_calc_pod_cpumask(target_attrs, cpu, off_cpu);
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if (wqattrs_equal(target_attrs, unbound_pwq(wq, cpu)->pool->attrs))
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pwq = rcu_dereference_protected(*per_cpu_ptr(wq->cpu_pwq, cpu),
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lockdep_is_held(&wq_pool_mutex));
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if (wqattrs_equal(target_attrs, pwq->pool->attrs))
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return;
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/* create a new pwq */
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@ -4587,11 +4574,10 @@ static void wq_update_pod(struct workqueue_struct *wq, int cpu,
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use_dfl_pwq:
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mutex_lock(&wq->mutex);
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pwq = unbound_pwq(wq, -1);
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raw_spin_lock_irq(&pwq->pool->lock);
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get_pwq(pwq);
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raw_spin_unlock_irq(&pwq->pool->lock);
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old_pwq = install_unbound_pwq(wq, cpu, pwq);
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raw_spin_lock_irq(&wq->dfl_pwq->pool->lock);
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get_pwq(wq->dfl_pwq);
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raw_spin_unlock_irq(&wq->dfl_pwq->pool->lock);
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old_pwq = install_unbound_pwq(wq, cpu, wq->dfl_pwq);
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out_unlock:
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mutex_unlock(&wq->mutex);
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put_pwq_unlocked(old_pwq);
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@ -4629,13 +4615,10 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq)
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cpus_read_lock();
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if (wq->flags & __WQ_ORDERED) {
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struct pool_workqueue *dfl_pwq;
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ret = apply_workqueue_attrs(wq, ordered_wq_attrs[highpri]);
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/* there should only be single pwq for ordering guarantee */
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dfl_pwq = rcu_access_pointer(wq->dfl_pwq);
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WARN(!ret && (wq->pwqs.next != &dfl_pwq->pwqs_node ||
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wq->pwqs.prev != &dfl_pwq->pwqs_node),
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WARN(!ret && (wq->pwqs.next != &wq->dfl_pwq->pwqs_node ||
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wq->pwqs.prev != &wq->dfl_pwq->pwqs_node),
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"ordering guarantee broken for workqueue %s\n", wq->name);
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} else {
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ret = apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]);
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@ -4866,7 +4849,7 @@ static bool pwq_busy(struct pool_workqueue *pwq)
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if (pwq->nr_in_flight[i])
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return true;
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if ((pwq != rcu_access_pointer(pwq->wq->dfl_pwq)) && (pwq->refcnt > 1))
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if ((pwq != pwq->wq->dfl_pwq) && (pwq->refcnt > 1))
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return true;
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if (!pwq_is_empty(pwq))
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return true;
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@ -4950,12 +4933,13 @@ void destroy_workqueue(struct workqueue_struct *wq)
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rcu_read_lock();
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for_each_possible_cpu(cpu) {
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put_pwq_unlocked(unbound_pwq(wq, cpu));
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RCU_INIT_POINTER(*unbound_pwq_slot(wq, cpu), NULL);
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pwq = rcu_access_pointer(*per_cpu_ptr(wq->cpu_pwq, cpu));
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RCU_INIT_POINTER(*per_cpu_ptr(wq->cpu_pwq, cpu), NULL);
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put_pwq_unlocked(pwq);
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}
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put_pwq_unlocked(unbound_pwq(wq, -1));
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RCU_INIT_POINTER(*unbound_pwq_slot(wq, -1), NULL);
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put_pwq_unlocked(wq->dfl_pwq);
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wq->dfl_pwq = NULL;
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rcu_read_unlock();
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}
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