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authorLinus Torvalds <torvalds@linux-foundation.org>2017-12-11 17:07:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-12-11 17:07:26 -0800
commit72dd379e67fb6c4f4b0ed8ee36e9fed78227f352 (patch)
tree929d5f049cd3b419ecf55124bf21ccd3bafcf74d /kernel
parenta83cb7e6ada140f8b932c223511f1063c4150870 (diff)
parent01dfee9582d9b4403c4902df096ed8b43d55181c (diff)
Merge branch 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo: - Lai's hotplug simplifications inadvertently fix a possible deadlock involving cpuset and workqueue - CPU isolation fix which was reverted due to the changes in the housekeeping code resurrected - A trivial unused include removal * 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove unneeded kallsyms include workqueue/hotplug: remove the workaround in rebind_workers() workqueue/hotplug: simplify workqueue_offline_cpu() workqueue: respect isolated cpus when queueing an unbound work main: kernel_start: move housekeeping_init() before workqueue_init_early()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/workqueue.c33
1 files changed, 12 insertions, 21 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 8fdb710bfdd7..43d18cb46308 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -38,7 +38,6 @@
#include <linux/hardirq.h>
#include <linux/mempolicy.h>
#include <linux/freezer.h>
-#include <linux/kallsyms.h>
#include <linux/debug_locks.h>
#include <linux/lockdep.h>
#include <linux/idr.h>
@@ -48,6 +47,7 @@
#include <linux/nodemask.h>
#include <linux/moduleparam.h>
#include <linux/uaccess.h>
+#include <linux/sched/isolation.h>
#include "workqueue_internal.h"
@@ -1634,7 +1634,7 @@ static void worker_enter_idle(struct worker *worker)
mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT);
/*
- * Sanity check nr_running. Because wq_unbind_fn() releases
+ * Sanity check nr_running. Because unbind_workers() releases
* pool->lock between setting %WORKER_UNBOUND and zapping
* nr_running, the warning may trigger spuriously. Check iff
* unbind is not in progress.
@@ -4510,9 +4510,8 @@ void show_workqueue_state(void)
* cpu comes back online.
*/
-static void wq_unbind_fn(struct work_struct *work)
+static void unbind_workers(int cpu)
{
- int cpu = smp_processor_id();
struct worker_pool *pool;
struct worker *worker;
@@ -4589,16 +4588,6 @@ static void rebind_workers(struct worker_pool *pool)
spin_lock_irq(&pool->lock);
- /*
- * XXX: CPU hotplug notifiers are weird and can call DOWN_FAILED
- * w/o preceding DOWN_PREPARE. Work around it. CPU hotplug is
- * being reworked and this can go away in time.
- */
- if (!(pool->flags & POOL_DISASSOCIATED)) {
- spin_unlock_irq(&pool->lock);
- return;
- }
-
pool->flags &= ~POOL_DISASSOCIATED;
for_each_pool_worker(worker, pool) {
@@ -4709,12 +4698,13 @@ int workqueue_online_cpu(unsigned int cpu)
int workqueue_offline_cpu(unsigned int cpu)
{
- struct work_struct unbind_work;
struct workqueue_struct *wq;
/* unbinding per-cpu workers should happen on the local CPU */
- INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
- queue_work_on(cpu, system_highpri_wq, &unbind_work);
+ if (WARN_ON(cpu != smp_processor_id()))
+ return -1;
+
+ unbind_workers(cpu);
/* update NUMA affinity of unbound workqueues */
mutex_lock(&wq_pool_mutex);
@@ -4722,9 +4712,6 @@ int workqueue_offline_cpu(unsigned int cpu)
wq_update_unbound_numa(wq, cpu, false);
mutex_unlock(&wq_pool_mutex);
- /* wait for per-cpu unbinding to finish */
- flush_work(&unbind_work);
- destroy_work_on_stack(&unbind_work);
return 0;
}
@@ -4957,6 +4944,10 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL))
return -ENOMEM;
+ /*
+ * Not excluding isolated cpus on purpose.
+ * If the user wishes to include them, we allow that.
+ */
cpumask_and(cpumask, cpumask, cpu_possible_mask);
if (!cpumask_empty(cpumask)) {
apply_wqattrs_lock();
@@ -5555,7 +5546,7 @@ int __init workqueue_init_early(void)
WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
- cpumask_copy(wq_unbound_cpumask, cpu_possible_mask);
+ cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(HK_FLAG_DOMAIN));
pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);