Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'wq-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
"Nothing too interesting. One patch to remove spurious warning and
others to address static checker warnings"
* tag 'wq-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Correct declaration of cpu_pwq in struct workqueue_struct
workqueue: Fix spruious data race in __flush_work()
workqueue: Remove incorrect "WARN_ON_ONCE(!list_empty(&worker->entry));" from dying worker
workqueue: Fix UBSAN 'subtraction overflow' error in shift_and_mask()
workqueue: doc: Fix function name, remove markers
+28
-24
+1
-1
Documentation/core-api/workqueue.rst
+1
-1
Documentation/core-api/workqueue.rst
···
260
260
is in flight at any given time and the work items are processed in
261
261
queueing order. While the combination of ``@max_active`` of 1 and
262
262
``WQ_UNBOUND`` used to achieve this behavior, this is no longer the
263
-
case. Use ``alloc_ordered_queue()`` instead.
263
+
case. Use alloc_ordered_workqueue() instead.
264
264
265
265
266
266
Example Execution Scenarios
+27
-23
kernel/workqueue.c
+27
-23
kernel/workqueue.c
···
377
377
378
378
/* hot fields used during command issue, aligned to cacheline */
379
379
unsigned int flags ____cacheline_aligned; /* WQ: WQ_* flags */
380
-
struct pool_workqueue __percpu __rcu **cpu_pwq; /* I: per-cpu pwqs */
380
+
struct pool_workqueue __rcu * __percpu *cpu_pwq; /* I: per-cpu pwqs */
381
381
struct wq_node_nr_active *node_nr_active[]; /* I: per-node nr_active */
382
382
};
383
383
···
897
897
898
898
static unsigned long shift_and_mask(unsigned long v, u32 shift, u32 bits)
899
899
{
900
-
return (v >> shift) & ((1 << bits) - 1);
900
+
return (v >> shift) & ((1U << bits) - 1);
901
901
}
902
902
903
903
static void work_offqd_unpack(struct work_offq_data *offqd, unsigned long data)
···
3351
3351
set_pf_worker(false);
3352
3352
3353
3353
ida_free(&pool->worker_ida, worker->id);
3354
-
WARN_ON_ONCE(!list_empty(&worker->entry));
3355
3354
return 0;
3356
3355
}
3357
3356
···
4166
4167
static bool __flush_work(struct work_struct *work, bool from_cancel)
4167
4168
{
4168
4169
struct wq_barrier barr;
4169
-
unsigned long data;
4170
4170
4171
4171
if (WARN_ON(!wq_online))
4172
4172
return false;
···
4183
4185
* was queued on a BH workqueue, we also know that it was running in the
4184
4186
* BH context and thus can be busy-waited.
4185
4187
*/
4186
-
data = *work_data_bits(work);
4187
-
if (from_cancel &&
4188
-
!WARN_ON_ONCE(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_BH)) {
4189
-
/*
4190
-
* On RT, prevent a live lock when %current preempted soft
4191
-
* interrupt processing or prevents ksoftirqd from running by
4192
-
* keeping flipping BH. If the BH work item runs on a different
4193
-
* CPU then this has no effect other than doing the BH
4194
-
* disable/enable dance for nothing. This is copied from
4195
-
* kernel/softirq.c::tasklet_unlock_spin_wait().
4196
-
*/
4197
-
while (!try_wait_for_completion(&barr.done)) {
4198
-
if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
4199
-
local_bh_disable();
4200
-
local_bh_enable();
4201
-
} else {
4202
-
cpu_relax();
4188
+
if (from_cancel) {
4189
+
unsigned long data = *work_data_bits(work);
4190
+
4191
+
if (!WARN_ON_ONCE(data & WORK_STRUCT_PWQ) &&
4192
+
(data & WORK_OFFQ_BH)) {
4193
+
/*
4194
+
* On RT, prevent a live lock when %current preempted
4195
+
* soft interrupt processing or prevents ksoftirqd from
4196
+
* running by keeping flipping BH. If the BH work item
4197
+
* runs on a different CPU then this has no effect other
4198
+
* than doing the BH disable/enable dance for nothing.
4199
+
* This is copied from
4200
+
* kernel/softirq.c::tasklet_unlock_spin_wait().
4201
+
*/
4202
+
while (!try_wait_for_completion(&barr.done)) {
4203
+
if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
4204
+
local_bh_disable();
4205
+
local_bh_enable();
4206
+
} else {
4207
+
cpu_relax();
4208
+
}
4203
4209
}
4210
+
goto out_destroy;
4204
4211
}
4205
-
} else {
4206
-
wait_for_completion(&barr.done);
4207
4212
}
4208
4213
4214
+
wait_for_completion(&barr.done);
4215
+
4216
+
out_destroy:
4209
4217
destroy_work_on_stack(&barr.work);
4210
4218
return true;
4211
4219
}