From a2775bbc1d58ce630517dfe86090c166f27d719f Mon Sep 17 00:00:00 2001 From: Mathieu Malaterre Date: Tue, 12 Mar 2019 21:21:26 +0100 Subject: kernel/workqueue: Use __printf markup to silence compiler in function 'alloc_workqueue' Silence warnings (triggered at W=1) by adding relevant __printf attributes. kernel/workqueue.c:4249:2: warning: function 'alloc_workqueue' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format] Signed-off-by: Mathieu Malaterre Signed-off-by: Tejun Heo --- kernel/workqueue.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4026d1871407..56b7cf898f10 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4208,6 +4208,7 @@ static int init_rescuer(struct workqueue_struct *wq) return 0; } +__printf(1, 4) struct workqueue_struct *alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...) -- cgit v1.2.3 From 8194fe94ab08f56ea55653df924647d23873d18c Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 19 Mar 2019 10:45:09 -0700 Subject: kernel/workqueue: Document wq_worker_last_func() argument This patch avoids that the following warning is reported when building with W=1: kernel/workqueue.c:938: warning: Function parameter or member 'task' not described in 'wq_worker_last_func' Signed-off-by: Bart Van Assche Signed-off-by: Tejun Heo --- kernel/workqueue.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 56b7cf898f10..21721faa923c 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -913,6 +913,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task) /** * wq_worker_last_func - retrieve worker's last work function + * @task: Task to retrieve last work function of. * * Determine the last function a worker executed. This is called from * the scheduler to get a worker's last known identity. -- cgit v1.2.3 From 24acfb71822566e4d469b4992a7b3b9f873e0083 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 13 Mar 2019 17:55:47 +0100 Subject: workqueue: Use normal rcu There is no need for sched_rcu. The undocumented reason why sched_rcu is used is to avoid a few explicit rcu_read_lock()/unlock() pairs by the fact that sched_rcu reader side critical sections are also protected by preempt or irq disabled regions. Replace rcu_read_lock_sched with rcu_read_lock and acquire the RCU lock where it is not yet explicit acquired. Replace local_irq_disable() with rcu_read_lock(). Update asserts. Signed-off-by: Thomas Gleixner [bigeasy: mangle changelog a little] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tejun Heo --- kernel/workqueue.c | 93 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 51 insertions(+), 42 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 21721faa923c..37a32884986b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -127,16 +127,16 @@ enum { * * PL: wq_pool_mutex protected. * - * PR: wq_pool_mutex protected for writes. Sched-RCU protected for reads. + * PR: wq_pool_mutex protected for writes. RCU protected for reads. * * PW: wq_pool_mutex and wq->mutex protected for writes. Either for reads. * * PWR: wq_pool_mutex and wq->mutex protected for writes. Either or - * sched-RCU for reads. + * RCU for reads. * * WQ: wq->mutex protected. * - * WR: wq->mutex protected for writes. Sched-RCU protected for reads. + * WR: wq->mutex protected for writes. RCU protected for reads. * * MD: wq_mayday_lock protected. */ @@ -183,7 +183,7 @@ struct worker_pool { atomic_t nr_running ____cacheline_aligned_in_smp; /* - * Destruction of pool is sched-RCU protected to allow dereferences + * Destruction of pool is RCU protected to allow dereferences * from get_work_pool(). */ struct rcu_head rcu; @@ -212,7 +212,7 @@ struct pool_workqueue { /* * Release of unbound pwq is punted to system_wq. See put_pwq() * and pwq_unbound_release_workfn() for details. pool_workqueue - * itself is also sched-RCU protected so that the first pwq can be + * itself is also RCU protected so that the first pwq can be * determined without grabbing wq->mutex. */ struct work_struct unbound_release_work; @@ -266,8 +266,8 @@ struct workqueue_struct { char name[WQ_NAME_LEN]; /* I: workqueue name */ /* - * Destruction of workqueue_struct is sched-RCU protected to allow - * walking the workqueues list without grabbing wq_pool_mutex. + * Destruction of workqueue_struct is RCU protected to allow walking + * the workqueues list without grabbing wq_pool_mutex. * This is used to dump all workqueues from sysrq. */ struct rcu_head rcu; @@ -359,20 +359,20 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); #include #define assert_rcu_or_pool_mutex() \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq_pool_mutex), \ - "sched RCU or wq_pool_mutex should be held") + "RCU or wq_pool_mutex should be held") #define assert_rcu_or_wq_mutex(wq) \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq->mutex), \ - "sched RCU or wq->mutex should be held") + "RCU or wq->mutex should be held") #define assert_rcu_or_wq_mutex_or_pool_mutex(wq) \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq->mutex) && \ !lockdep_is_held(&wq_pool_mutex), \ - "sched RCU, wq->mutex or wq_pool_mutex should be held") + "RCU, wq->mutex or wq_pool_mutex should be held") #define for_each_cpu_worker_pool(pool, cpu) \ for ((pool) = &per_cpu(cpu_worker_pools, cpu)[0]; \ @@ -384,7 +384,7 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); * @pool: iteration cursor * @pi: integer used for iteration * - * This must be called either with wq_pool_mutex held or sched RCU read + * This must be called either with wq_pool_mutex held or RCU read * locked. If the pool needs to be used beyond the locking in effect, the * caller is responsible for guaranteeing that the pool stays online. * @@ -416,7 +416,7 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); * @pwq: iteration cursor * @wq: the target workqueue * - * This must be called either with wq->mutex held or sched RCU read locked. + * This must be called either with wq->mutex held or RCU read locked. * If the pwq needs to be used beyond the locking in effect, the caller is * responsible for guaranteeing that the pwq stays online. * @@ -552,7 +552,7 @@ static int worker_pool_assign_id(struct worker_pool *pool) * @wq: the target workqueue * @node: the node ID * - * This must be called with any of wq_pool_mutex, wq->mutex or sched RCU + * This must be called with any of wq_pool_mutex, wq->mutex or RCU * read locked. * If the pwq needs to be used beyond the locking in effect, the caller is * responsible for guaranteeing that the pwq stays online. @@ -696,8 +696,8 @@ static struct pool_workqueue *get_work_pwq(struct work_struct *work) * @work: the work item of interest * * Pools are created and destroyed under wq_pool_mutex, and allows read - * access under sched-RCU read lock. As such, this function should be - * called under wq_pool_mutex or with preemption disabled. + * access under RCU read lock. As such, this function should be + * called under wq_pool_mutex or inside of a rcu_read_lock() region. * * All fields of the returned pool are accessible as long as the above * mentioned locking is in effect. If the returned pool needs to be used @@ -1133,7 +1133,7 @@ static void put_pwq_unlocked(struct pool_workqueue *pwq) { if (pwq) { /* - * As both pwqs and pools are sched-RCU protected, the + * As both pwqs and pools are RCU protected, the * following lock operations are safe. */ spin_lock_irq(&pwq->pool->lock); @@ -1261,6 +1261,7 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork, if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) return 0; + rcu_read_lock(); /* * The queueing is in progress, or it is already queued. Try to * steal it from ->worklist without clearing WORK_STRUCT_PENDING. @@ -1299,10 +1300,12 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork, set_work_pool_and_keep_pending(work, pool->id); spin_unlock(&pool->lock); + rcu_read_unlock(); return 1; } spin_unlock(&pool->lock); fail: + rcu_read_unlock(); local_irq_restore(*flags); if (work_is_canceling(work)) return -ENOENT; @@ -1416,6 +1419,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, if (unlikely(wq->flags & __WQ_DRAINING) && WARN_ON_ONCE(!is_chained_work(wq))) return; + rcu_read_lock(); retry: if (req_cpu == WORK_CPU_UNBOUND) cpu = wq_select_unbound_cpu(raw_smp_processor_id()); @@ -1472,10 +1476,8 @@ retry: /* pwq determined, queue */ trace_workqueue_queue_work(req_cpu, pwq, work); - if (WARN_ON(!list_empty(&work->entry))) { - spin_unlock(&pwq->pool->lock); - return; - } + if (WARN_ON(!list_empty(&work->entry))) + goto out; pwq->nr_in_flight[pwq->work_color]++; work_flags = work_color_to_flags(pwq->work_color); @@ -1493,7 +1495,9 @@ retry: insert_work(pwq, work, worklist, work_flags); +out: spin_unlock(&pwq->pool->lock); + rcu_read_unlock(); } /** @@ -2975,14 +2979,14 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, might_sleep(); - local_irq_disable(); + rcu_read_lock(); pool = get_work_pool(work); if (!pool) { - local_irq_enable(); + rcu_read_unlock(); return false; } - spin_lock(&pool->lock); + spin_lock_irq(&pool->lock); /* see the comment in try_to_grab_pending() with the same code */ pwq = get_work_pwq(work); if (pwq) { @@ -3014,10 +3018,11 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, lock_map_acquire(&pwq->wq->lockdep_map); lock_map_release(&pwq->wq->lockdep_map); } - + rcu_read_unlock(); return true; already_gone: spin_unlock_irq(&pool->lock); + rcu_read_unlock(); return false; } @@ -3504,7 +3509,7 @@ static void rcu_free_pool(struct rcu_head *rcu) * put_unbound_pool - put a worker_pool * @pool: worker_pool to put * - * Put @pool. If its refcnt reaches zero, it gets destroyed in sched-RCU + * Put @pool. If its refcnt reaches zero, it gets destroyed in RCU * safe manner. get_unbound_pool() calls this function on its failure path * and this function should be able to release pools which went through, * successfully or not, init_worker_pool(). @@ -3558,7 +3563,7 @@ static void put_unbound_pool(struct worker_pool *pool) del_timer_sync(&pool->idle_timer); del_timer_sync(&pool->mayday_timer); - /* sched-RCU protected to allow dereferences from get_work_pool() */ + /* RCU protected to allow dereferences from get_work_pool() */ call_rcu(&pool->rcu, rcu_free_pool); } @@ -4472,7 +4477,8 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq) struct pool_workqueue *pwq; bool ret; - rcu_read_lock_sched(); + rcu_read_lock(); + preempt_disable(); if (cpu == WORK_CPU_UNBOUND) cpu = smp_processor_id(); @@ -4483,7 +4489,8 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq) pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); ret = !list_empty(&pwq->delayed_works); - rcu_read_unlock_sched(); + preempt_enable(); + rcu_read_unlock(); return ret; } @@ -4509,15 +4516,15 @@ unsigned int work_busy(struct work_struct *work) if (work_pending(work)) ret |= WORK_BUSY_PENDING; - local_irq_save(flags); + rcu_read_lock(); pool = get_work_pool(work); if (pool) { - spin_lock(&pool->lock); + spin_lock_irqsave(&pool->lock, flags); if (find_worker_executing_work(pool, work)) ret |= WORK_BUSY_RUNNING; - spin_unlock(&pool->lock); + spin_unlock_irqrestore(&pool->lock, flags); } - local_irq_restore(flags); + rcu_read_unlock(); return ret; } @@ -4701,7 +4708,7 @@ void show_workqueue_state(void) unsigned long flags; int pi; - rcu_read_lock_sched(); + rcu_read_lock(); pr_info("Showing busy workqueues and worker pools:\n"); @@ -4766,7 +4773,7 @@ void show_workqueue_state(void) touch_nmi_watchdog(); } - rcu_read_unlock_sched(); + rcu_read_unlock(); } /* used to show worker information through /proc/PID/{comm,stat,status} */ @@ -5153,16 +5160,16 @@ bool freeze_workqueues_busy(void) * nr_active is monotonically decreasing. It's safe * to peek without lock. */ - rcu_read_lock_sched(); + rcu_read_lock(); for_each_pwq(pwq, wq) { WARN_ON_ONCE(pwq->nr_active < 0); if (pwq->nr_active) { busy = true; - rcu_read_unlock_sched(); + rcu_read_unlock(); goto out_unlock; } } - rcu_read_unlock_sched(); + rcu_read_unlock(); } out_unlock: mutex_unlock(&wq_pool_mutex); @@ -5357,7 +5364,8 @@ static ssize_t wq_pool_ids_show(struct device *dev, const char *delim = ""; int node, written = 0; - rcu_read_lock_sched(); + get_online_cpus(); + rcu_read_lock(); for_each_node(node) { written += scnprintf(buf + written, PAGE_SIZE - written, "%s%d:%d", delim, node, @@ -5365,7 +5373,8 @@ static ssize_t wq_pool_ids_show(struct device *dev, delim = " "; } written += scnprintf(buf + written, PAGE_SIZE - written, "\n"); - rcu_read_unlock_sched(); + rcu_read_unlock(); + put_online_cpus(); return written; } -- cgit v1.2.3 From d75f773c86a2b8b7278e2c33343b46a4024bc002 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 25 Mar 2019 21:32:28 +0200 Subject: treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively %pF and %pf are functionally equivalent to %pS and %ps conversion specifiers. The former are deprecated, therefore switch the current users to use the preferred variant. The changes have been produced by the following command: git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \ while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done And verifying the result. Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com Cc: Andy Shevchenko Cc: linux-arm-kernel@lists.infradead.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: xen-devel@lists.xenproject.org Cc: linux-acpi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: linux-pci@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-btrfs@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-mm@kvack.org Cc: ceph-devel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Sakari Ailus Acked-by: David Sterba (for btrfs) Acked-by: Mike Rapoport (for mm/memblock.c) Acked-by: Bjorn Helgaas (for drivers/pci) Acked-by: Rafael J. Wysocki Signed-off-by: Petr Mladek --- kernel/workqueue.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 7abbeed13421..8ea9e4fb8cc6 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2277,7 +2277,7 @@ __acquires(&pool->lock) if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { pr_err("BUG: workqueue leaked lock or atomic: %s/0x%08x/%d\n" - " last function: %pf\n", + " last function: %ps\n", current->comm, preempt_count(), task_pid_nr(current), worker->current_func); debug_show_held_locks(current); @@ -2596,11 +2596,11 @@ static void check_flush_dependency(struct workqueue_struct *target_wq, worker = current_wq_worker(); WARN_ONCE(current->flags & PF_MEMALLOC, - "workqueue: PF_MEMALLOC task %d(%s) is flushing !WQ_MEM_RECLAIM %s:%pf", + "workqueue: PF_MEMALLOC task %d(%s) is flushing !WQ_MEM_RECLAIM %s:%ps", current->pid, current->comm, target_wq->name, target_func); WARN_ONCE(worker && ((worker->current_pwq->wq->flags & (WQ_MEM_RECLAIM | __WQ_LEGACY)) == WQ_MEM_RECLAIM), - "workqueue: WQ_MEM_RECLAIM %s:%pf is flushing !WQ_MEM_RECLAIM %s:%pf", + "workqueue: WQ_MEM_RECLAIM %s:%ps is flushing !WQ_MEM_RECLAIM %s:%ps", worker->current_pwq->wq->name, worker->current_func, target_wq->name, target_func); } @@ -4582,7 +4582,7 @@ void print_worker_info(const char *log_lvl, struct task_struct *task) probe_kernel_read(desc, worker->desc, sizeof(desc) - 1); if (fn || name[0] || desc[0]) { - printk("%sWorkqueue: %s %pf", log_lvl, name, fn); + printk("%sWorkqueue: %s %ps", log_lvl, name, fn); if (strcmp(name, desc)) pr_cont(" (%s)", desc); pr_cont("\n"); @@ -4607,7 +4607,7 @@ static void pr_cont_work(bool comma, struct work_struct *work) pr_cont("%s BAR(%d)", comma ? "," : "", task_pid_nr(barr->task)); } else { - pr_cont("%s %pf", comma ? "," : "", work->func); + pr_cont("%s %ps", comma ? "," : "", work->func); } } @@ -4639,7 +4639,7 @@ static void show_pwq(struct pool_workqueue *pwq) if (worker->current_pwq != pwq) continue; - pr_cont("%s %d%s:%pf", comma ? "," : "", + pr_cont("%s %d%s:%ps", comma ? "," : "", task_pid_nr(worker->task), worker == pwq->wq->rescuer ? "(RESCUER)" : "", worker->current_func); -- cgit v1.2.3 From 457c89965399115e5cd8bf38f9c597293405703d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 19 May 2019 13:08:55 +0100 Subject: treewide: Add SPDX license identifier for missed files Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/workqueue.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 9657315405de..95aea04ff722 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * kernel/workqueue.c - generic async execution with shared worker pool * -- cgit v1.2.3