user/sven/linux.git/include/linux/workqueue.h, branch v4.12.4

workqueue: Provide work_on_cpu_safe()

2017-04-15T10:20:53Z

work_on_cpu() is not protected against CPU hotplug. For code which requires to be either executed on an online CPU or to fail if the CPU is not available the callsite would have to protect against CPU hotplug. Provide a function which does get/put_online_cpus() around the call to work_on_cpu() and fails the call with -ENODEV if the target CPU is not online. Preparatory patch to convert several racy task affinity manipulations. Signed-off-by: Thomas Gleixner Acked-by: Tejun Heo Cc: Fenghua Yu Cc: Tony Luck Cc: Herbert Xu Cc: "Rafael J. Wysocki" Cc: Peter Zijlstra Cc: Benjamin Herrenschmidt Cc: Sebastian Siewior Cc: Lai Jiangshan Cc: Viresh Kumar Cc: Michael Ellerman Cc: "David S. Miller" Cc: Len Brown Link: http://lkml.kernel.org/r/20170412201042.262610721@linutronix.de Signed-off-by: Thomas Gleixner

workqueue: avoid clang warning

2017-02-02T20:22:18Z

Building with clang shows lots of warning like: drivers/amba/bus.c:447:8: warning: implicit conversion from 'long long' to 'int' changes value from 4294967248 to -48 [-Wconstant-conversion] static DECLARE_DELAYED_WORK(deferred_retry_work, amba_deferred_retry_func); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/workqueue.h:187:26: note: expanded from macro 'DECLARE_DELAYED_WORK' struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/workqueue.h:177:10: note: expanded from macro '__DELAYED_WORK_INITIALIZER' .work = __WORK_INITIALIZER((n).work, (f)), \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/workqueue.h:170:10: note: expanded from macro '__WORK_INITIALIZER' .data = WORK_DATA_STATIC_INIT(), \ ^~~~~~~~~~~~~~~~~~~~~~~ include/linux/workqueue.h:111:39: note: expanded from macro 'WORK_DATA_STATIC_INIT' ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~ include/asm-generic/atomic-long.h:32:41: note: expanded from macro 'ATOMIC_LONG_INIT' #define ATOMIC_LONG_INIT(i) ATOMIC_INIT(i) ~~~~~~~~~~~~^~ arch/arm/include/asm/atomic.h:21:27: note: expanded from macro 'ATOMIC_INIT' #define ATOMIC_INIT(i) { (i) } ~ ^ This makes the type cast explicit, which shuts up the warning. Signed-off-by: Arnd Bergmann Signed-off-by: Tejun Heo

Merge branch 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2016-12-13T20:59:57Z

Pull workqueue updates from Tejun Heo: "Mostly patches to initialize workqueue subsystem earlier and get rid of keventd_up(). The patches were headed for the last merge cycle but got delayed due to a bug found late minute, which is fixed now. Also, to help debugging, destroy_workqueue() is more chatty now on a sanity check failure." * 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: move wq_numa_init() to workqueue_init() workqueue: remove keventd_up() debugobj, workqueue: remove keventd_up() usage slab, workqueue: remove keventd_up() usage power, workqueue: remove keventd_up() usage tty, workqueue: remove keventd_up() usage mce, workqueue: remove keventd_up() usage workqueue: make workqueue available early during boot workqueue: dump workqueue state on sanity check failures in destroy_workqueue()

workqueue: kerneldocify workqueue_attrs

2016-10-28T16:54:32Z

Only formating changes. Signed-off-by: Silvio Fricke Acked-by: Tejun Heo Signed-off-by: Jonathan Corbet

Merge branch 'for-4.9' into for-4.10

2016-10-19T16:12:40Z

workqueue: remove keventd_up()

2016-09-17T17:18:21Z

keventd_up() no longer has in-kernel users. Remove it and make wq_online static. Signed-off-by: Tejun Heo

workqueue: make workqueue available early during boot

2016-09-17T17:18:21Z

Workqueue is currently initialized in an early init call; however, there are cases where early boot code has to be split and reordered to come after workqueue initialization or the same code path which makes use of workqueues is used both before workqueue initailization and after. The latter cases have to gate workqueue usages with keventd_up() tests, which is nasty and easy to get wrong. Workqueue usages have become widespread and it'd be a lot more convenient if it can be used very early from boot. This patch splits workqueue initialization into two steps. workqueue_init_early() which sets up the basic data structures so that workqueues can be created and work items queued, and workqueue_init() which actually brings up workqueues online and starts executing queued work items. The former step can be done very early during boot once memory allocation, cpumasks and idr are initialized. The latter right after kthreads become available. This allows work item queueing and canceling from very early boot which is what most of these use cases want. * As systemd_wq being initialized doesn't indicate that workqueue is fully online anymore, update keventd_up() to test wq_online instead. The follow-up patches will get rid of all its usages and the function itself. * Flushing doesn't make sense before workqueue is fully initialized. The flush functions trigger WARN and return immediately before fully online. * Work items are never in-flight before fully online. Canceling can always succeed by skipping the flush step. * Some code paths can no longer assume to be called with irq enabled as irq is disabled during early boot. Use irqsave/restore operations instead. v2: Watchdog init, which requires timer to be running, moved from workqueue_init_early() to workqueue_init(). Signed-off-by: Tejun Heo Suggested-by: Linus Torvalds Link: http://lkml.kernel.org/r/CA+55aFx0vPuMuxn00rBSM192n-Du5uxy+4AvKa0SBSOVJeuCGg@mail.gmail.com

workqueue: add cancel_work()

2016-08-29T14:13:21Z

Like cancel_delayed_work(), but for regular work. Signed-off-by: Jens Axboe Mehed-by: Tejun Heo Acked-by: Tejun Heo

workqueue: Convert to state machine callbacks

2016-07-14T07:34:43Z

Get rid of the prio ordering of the separate notifiers and use a proper state callback pair. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Acked-by: Tejun Heo Cc: Andrew Morton Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Nicolas Iooss Cc: Oleg Nesterov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Rusty Russell Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153335.197083890@linutronix.de Signed-off-by: Ingo Molnar

workqueue: skip flush dependency checks for legacy workqueues

2016-01-29T18:31:10Z

fca839c00a12 ("workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue") implemented flush dependency warning which triggers if a PF_MEMALLOC task or WQ_MEM_RECLAIM workqueue tries to flush a !WQ_MEM_RECLAIM workquee. This assumes that workqueues marked with WQ_MEM_RECLAIM sit in memory reclaim path and making it depend on something which may need more memory to make forward progress can lead to deadlocks. Unfortunately, workqueues created with the legacy create*_workqueue() interface always have WQ_MEM_RECLAIM regardless of whether they are depended upon memory reclaim or not. These spurious WQ_MEM_RECLAIM markings cause spurious triggering of the flush dependency checks. WARNING: CPU: 0 PID: 6 at kernel/workqueue.c:2361 check_flush_dependency+0x138/0x144() workqueue: WQ_MEM_RECLAIM deferwq:deferred_probe_work_func is flushing !WQ_MEM_RECLAIM events:lru_add_drain_per_cpu ... Workqueue: deferwq deferred_probe_work_func [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x94/0xd4) [] (dump_stack) from [] (warn_slowpath_common+0x80/0xb0) [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x30/0x40) [] (warn_slowpath_fmt) from [] (check_flush_dependency+0x138/0x144) [] (check_flush_dependency) from [] (flush_work+0x50/0x15c) [] (flush_work) from [] (lru_add_drain_all+0x130/0x180) [] (lru_add_drain_all) from [] (migrate_prep+0x8/0x10) [] (migrate_prep) from [] (alloc_contig_range+0xd8/0x338) [] (alloc_contig_range) from [] (cma_alloc+0xe0/0x1ac) [] (cma_alloc) from [] (__alloc_from_contiguous+0x38/0xd8) [] (__alloc_from_contiguous) from [] (__dma_alloc+0x240/0x278) [] (__dma_alloc) from [] (arm_dma_alloc+0x54/0x5c) [] (arm_dma_alloc) from [] (dmam_alloc_coherent+0xc0/0xec) [] (dmam_alloc_coherent) from [] (ahci_port_start+0x150/0x1dc) [] (ahci_port_start) from [] (ata_host_start.part.3+0xc8/0x1c8) [] (ata_host_start.part.3) from [] (ata_host_activate+0x50/0x148) [] (ata_host_activate) from [] (ahci_host_activate+0x44/0x114) [] (ahci_host_activate) from [] (ahci_platform_init_host+0x1d8/0x3c8) [] (ahci_platform_init_host) from [] (tegra_ahci_probe+0x448/0x4e8) [] (tegra_ahci_probe) from [] (platform_drv_probe+0x50/0xac) [] (platform_drv_probe) from [] (driver_probe_device+0x214/0x2c0) [] (driver_probe_device) from [] (bus_for_each_drv+0x60/0x94) [] (bus_for_each_drv) from [] (__device_attach+0xb0/0x114) [] (__device_attach) from [] (bus_probe_device+0x84/0x8c) [] (bus_probe_device) from [] (deferred_probe_work_func+0x68/0x98) [] (deferred_probe_work_func) from [] (process_one_work+0x120/0x3f8) [] (process_one_work) from [] (worker_thread+0x38/0x55c) [] (worker_thread) from [] (kthread+0xdc/0xf4) [] (kthread) from [] (ret_from_fork+0x14/0x3c) Fix it by marking workqueues created via create*_workqueue() with __WQ_LEGACY and disabling flush dependency checks on them. Signed-off-by: Tejun Heo Reported-and-tested-by: Thierry Reding Link: http://lkml.kernel.org/g/20160126173843.GA11115@ulmo.nvidia.com Fixes: fca839c00a12 ("workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue")