Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/tj/wq

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove in_workqueue_context()
  workqueue: Clarify that schedule_on_each_cpu is synchronous
  memory_hotplug: drop spurious calls to flush_scheduled_work()
  shpchp: update workqueue usage
  pciehp: update workqueue usage
  isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
  workqueue: add and use WQ_MEM_RECLAIM flag
  workqueue: fix HIGHPRI handling in keep_working()
  workqueue: add queue_work and activate_work trace points
  workqueue: prepare for more tracepoints
  workqueue: implement flush[_delayed]_work_sync()
  workqueue: factor out start_flush_work()
  workqueue: cleanup flush/cancel functions
  workqueue: implement alloc_ordered_workqueue()

Fix up trivial conflict in fs/gfs2/main.c as per Tejun

Documentation/workqueue.txt

@@ -196,11 +196,11 @@ resources, scheduled and executed.
 	suspend operations.  Work items on the wq are drained and no
 	new work item starts execution until thawed.
 
-  WQ_RESCUER
+  WQ_MEM_RECLAIM
 
 	All wq which might be used in the memory reclaim paths _MUST_
-	have this flag set.  This reserves one worker exclusively for
-	the execution of this wq under memory pressure.
+	have this flag set.  The wq is guaranteed to have at least one
+	execution context regardless of memory pressure.
 
   WQ_HIGHPRI
 
@@ -356,24 +356,25 @@ If q1 has WQ_CPU_INTENSIVE set,
 
 6. Guidelines
 
-* Do not forget to use WQ_RESCUER if a wq may process work items which
-  are used during memory reclaim.  Each wq with WQ_RESCUER set has one
-  rescuer thread reserved for it.  If there is dependency among
-  multiple work items used during memory reclaim, they should be
-  queued to separate wq each with WQ_RESCUER.
+* Do not forget to use WQ_MEM_RECLAIM if a wq may process work items
+  which are used during memory reclaim.  Each wq with WQ_MEM_RECLAIM
+  set has an execution context reserved for it.  If there is
+  dependency among multiple work items used during memory reclaim,
+  they should be queued to separate wq each with WQ_MEM_RECLAIM.
 
 * Unless strict ordering is required, there is no need to use ST wq.
 
 * Unless there is a specific need, using 0 for @max_active is
   recommended.  In most use cases, concurrency level usually stays
   well under the default limit.
 
-* A wq serves as a domain for forward progress guarantee (WQ_RESCUER),
-  flush and work item attributes.  Work items which are not involved
-  in memory reclaim and don't need to be flushed as a part of a group
-  of work items, and don't require any special attribute, can use one
-  of the system wq.  There is no difference in execution
-  characteristics between using a dedicated wq and a system wq.
+* A wq serves as a domain for forward progress guarantee
+  (WQ_MEM_RECLAIM, flush and work item attributes.  Work items which
+  are not involved in memory reclaim and don't need to be flushed as a
+  part of a group of work items, and don't require any special
+  attribute, can use one of the system wq.  There is no difference in
+  execution characteristics between using a dedicated wq and a system
+  wq.
 
 * Unless work items are expected to consume a huge amount of CPU
   cycles, using a bound wq is usually beneficial due to the increased

drivers/ata/libata-sff.c

@@ -3335,7 +3335,7 @@ void ata_sff_port_init(struct ata_port *ap)
 
 int __init ata_sff_init(void)
 {
-	ata_sff_wq = alloc_workqueue("ata_sff", WQ_RESCUER, WQ_MAX_ACTIVE);
+	ata_sff_wq = alloc_workqueue("ata_sff", WQ_MEM_RECLAIM, WQ_MAX_ACTIVE);
 	if (!ata_sff_wq)
 		return -ENOMEM;
 

drivers/isdn/hardware/eicon/divasmain.c

@@ -15,7 +15,6 @@
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <linux/ioport.h>
-#include <linux/workqueue.h>
 #include <linux/pci.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
@@ -546,7 +545,6 @@ void diva_os_remove_soft_isr(diva_os_soft_isr_t * psoft_isr)
 		void *mem;
 
 		tasklet_kill(&pdpc->divas_task);
-		flush_scheduled_work();
 		mem = psoft_isr->object;
 		psoft_isr->object = NULL;
 		diva_os_free(0, mem);

drivers/pci/hotplug/pciehp.h

@@ -36,6 +36,7 @@
 #include <linux/sched.h>		/* signal_pending() */
 #include <linux/pcieport_if.h>
 #include <linux/mutex.h>
+#include <linux/workqueue.h>
 
 #define MY_NAME	"pciehp"
 
@@ -44,6 +45,7 @@ extern int pciehp_poll_time;
 extern int pciehp_debug;
 extern int pciehp_force;
 extern struct workqueue_struct *pciehp_wq;
+extern struct workqueue_struct *pciehp_ordered_wq;
 
 #define dbg(format, arg...)						\
 do {									\

drivers/pci/hotplug/pciehp_core.c

@@ -43,6 +43,7 @@ int pciehp_poll_mode;
 int pciehp_poll_time;
 int pciehp_force;
 struct workqueue_struct *pciehp_wq;
+struct workqueue_struct *pciehp_ordered_wq;
 
 #define DRIVER_VERSION	"0.4"
 #define DRIVER_AUTHOR	"Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
@@ -340,18 +341,33 @@ static int __init pcied_init(void)
 {
 	int retval = 0;
 
+	pciehp_wq = alloc_workqueue("pciehp", 0, 0);
+	if (!pciehp_wq)
+		return -ENOMEM;
+
+	pciehp_ordered_wq = alloc_ordered_workqueue("pciehp_ordered", 0);
+	if (!pciehp_ordered_wq) {
+		destroy_workqueue(pciehp_wq);
+		return -ENOMEM;
+	}
+
 	pciehp_firmware_init();
 	retval = pcie_port_service_register(&hpdriver_portdrv);
  	dbg("pcie_port_service_register = %d\n", retval);
   	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
- 	if (retval)
+ 	if (retval) {
+		destroy_workqueue(pciehp_ordered_wq);
+		destroy_workqueue(pciehp_wq);
 		dbg("Failure to register service\n");
+	}
 	return retval;
 }
 
 static void __exit pcied_cleanup(void)
 {
 	dbg("unload_pciehpd()\n");
+	destroy_workqueue(pciehp_ordered_wq);
+	destroy_workqueue(pciehp_wq);
 	pcie_port_service_unregister(&hpdriver_portdrv);
 	info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
 }

drivers/pci/hotplug/pciehp_ctrl.c

@@ -32,7 +32,6 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/pci.h>
-#include <linux/workqueue.h>
 #include "../pci.h"
 #include "pciehp.h"
 
@@ -50,7 +49,7 @@ static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
 	info->p_slot = p_slot;
 	INIT_WORK(&info->work, interrupt_event_handler);
 
-	schedule_work(&info->work);
+	queue_work(pciehp_wq, &info->work);
 
 	return 0;
 }
@@ -345,7 +344,7 @@ void pciehp_queue_pushbutton_work(struct work_struct *work)
 		kfree(info);
 		goto out;
 	}
-	queue_work(pciehp_wq, &info->work);
+	queue_work(pciehp_ordered_wq, &info->work);
  out:
 	mutex_unlock(&p_slot->lock);
 }
@@ -378,7 +377,7 @@ static void handle_button_press_event(struct slot *p_slot)
 		if (ATTN_LED(ctrl))
 			pciehp_set_attention_status(p_slot, 0);
 
-		schedule_delayed_work(&p_slot->work, 5*HZ);
+		queue_delayed_work(pciehp_wq, &p_slot->work, 5*HZ);
 		break;
 	case BLINKINGOFF_STATE:
 	case BLINKINGON_STATE:
@@ -440,7 +439,7 @@ static void handle_surprise_event(struct slot *p_slot)
 	else
 		p_slot->state = POWERON_STATE;
 
-	queue_work(pciehp_wq, &info->work);
+	queue_work(pciehp_ordered_wq, &info->work);
 }
 
 static void interrupt_event_handler(struct work_struct *work)

drivers/pci/hotplug/pciehp_hpc.c

@@ -41,8 +41,6 @@
 #include "../pci.h"
 #include "pciehp.h"
 
-static atomic_t pciehp_num_controllers = ATOMIC_INIT(0);
-
 static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
 {
 	struct pci_dev *dev = ctrl->pcie->port;
@@ -805,8 +803,8 @@ static void pcie_cleanup_slot(struct controller *ctrl)
 {
 	struct slot *slot = ctrl->slot;
 	cancel_delayed_work(&slot->work);
-	flush_scheduled_work();
 	flush_workqueue(pciehp_wq);
+	flush_workqueue(pciehp_ordered_wq);
 	kfree(slot);
 }
 
@@ -912,16 +910,6 @@ struct controller *pcie_init(struct pcie_device *dev)
 	/* Disable sotfware notification */
 	pcie_disable_notification(ctrl);
 
-	/*
-	 * If this is the first controller to be initialized,
-	 * initialize the pciehp work queue
-	 */
-	if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
-		pciehp_wq = create_singlethread_workqueue("pciehpd");
-		if (!pciehp_wq)
-			goto abort_ctrl;
-	}
-
 	ctrl_info(ctrl, "HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n",
 		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
 		  pdev->subsystem_device);
@@ -941,11 +929,5 @@ void pciehp_release_ctrl(struct controller *ctrl)
 {
 	pcie_shutdown_notification(ctrl);
 	pcie_cleanup_slot(ctrl);
-	/*
-	 * If this is the last controller to be released, destroy the
-	 * pciehp work queue
-	 */
-	if (atomic_dec_and_test(&pciehp_num_controllers))
-		destroy_workqueue(pciehp_wq);
 	kfree(ctrl);
 }

drivers/pci/hotplug/shpchp.h

@@ -35,6 +35,7 @@
 #include <linux/delay.h>
 #include <linux/sched.h>	/* signal_pending(), struct timer_list */
 #include <linux/mutex.h>
+#include <linux/workqueue.h>
 
 #if !defined(MODULE)
 	#define MY_NAME	"shpchp"
@@ -46,6 +47,7 @@ extern int shpchp_poll_mode;
 extern int shpchp_poll_time;
 extern int shpchp_debug;
 extern struct workqueue_struct *shpchp_wq;
+extern struct workqueue_struct *shpchp_ordered_wq;
 
 #define dbg(format, arg...)						\
 do {									\

drivers/pci/hotplug/shpchp_core.c

@@ -33,14 +33,14 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/pci.h>
-#include <linux/workqueue.h>
 #include "shpchp.h"
 
 /* Global variables */
 int shpchp_debug;
 int shpchp_poll_mode;
 int shpchp_poll_time;
 struct workqueue_struct *shpchp_wq;
+struct workqueue_struct *shpchp_ordered_wq;
 
 #define DRIVER_VERSION	"0.4"
 #define DRIVER_AUTHOR	"Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
@@ -174,8 +174,8 @@ void cleanup_slots(struct controller *ctrl)
 		slot = list_entry(tmp, struct slot, slot_list);
 		list_del(&slot->slot_list);
 		cancel_delayed_work(&slot->work);
-		flush_scheduled_work();
 		flush_workqueue(shpchp_wq);
+		flush_workqueue(shpchp_ordered_wq);
 		pci_hp_deregister(slot->hotplug_slot);
 	}
 }
@@ -360,16 +360,32 @@ static int __init shpcd_init(void)
 {
 	int retval = 0;
 
+	shpchp_wq = alloc_ordered_workqueue("shpchp", 0);
+	if (!shpchp_wq)
+		return -ENOMEM;
+
+	shpchp_ordered_wq = alloc_ordered_workqueue("shpchp_ordered", 0);
+	if (!shpchp_ordered_wq) {
+		destroy_workqueue(shpchp_wq);
+		return -ENOMEM;
+	}
+
 	retval = pci_register_driver(&shpc_driver);
 	dbg("%s: pci_register_driver = %d\n", __func__, retval);
 	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
+	if (retval) {
+		destroy_workqueue(shpchp_ordered_wq);
+		destroy_workqueue(shpchp_wq);
+	}
 	return retval;
 }
 
 static void __exit shpcd_cleanup(void)
 {
 	dbg("unload_shpchpd()\n");
 	pci_unregister_driver(&shpc_driver);
+	destroy_workqueue(shpchp_ordered_wq);
+	destroy_workqueue(shpchp_wq);
 	info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
 }
 

drivers/pci/hotplug/shpchp_ctrl.c

@@ -32,7 +32,6 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/pci.h>
-#include <linux/workqueue.h>
 #include "../pci.h"
 #include "shpchp.h"
 
@@ -52,7 +51,7 @@ static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
 	info->p_slot = p_slot;
 	INIT_WORK(&info->work, interrupt_event_handler);
 
-	schedule_work(&info->work);
+	queue_work(shpchp_wq, &info->work);
 
 	return 0;
 }
@@ -457,7 +456,7 @@ void shpchp_queue_pushbutton_work(struct work_struct *work)
 		kfree(info);
 		goto out;
 	}
-	queue_work(shpchp_wq, &info->work);
+	queue_work(shpchp_ordered_wq, &info->work);
  out:
 	mutex_unlock(&p_slot->lock);
 }
@@ -505,7 +504,7 @@ static void handle_button_press_event(struct slot *p_slot)
 		p_slot->hpc_ops->green_led_blink(p_slot);
 		p_slot->hpc_ops->set_attention_status(p_slot, 0);
 
-		schedule_delayed_work(&p_slot->work, 5*HZ);
+		queue_delayed_work(shpchp_wq, &p_slot->work, 5*HZ);
 		break;
 	case BLINKINGOFF_STATE:
 	case BLINKINGON_STATE:

drivers/pci/hotplug/shpchp_hpc.c

@@ -179,8 +179,6 @@
 #define SLOT_EVENT_LATCH	0x2
 #define SLOT_SERR_INT_MASK	0x3
 
-static atomic_t shpchp_num_controllers = ATOMIC_INIT(0);
-
 static irqreturn_t shpc_isr(int irq, void *dev_id);
 static void start_int_poll_timer(struct controller *ctrl, int sec);
 static int hpc_check_cmd_status(struct controller *ctrl);
@@ -614,13 +612,6 @@ static void hpc_release_ctlr(struct controller *ctrl)
 
 	iounmap(ctrl->creg);
 	release_mem_region(ctrl->mmio_base, ctrl->mmio_size);
-
-	/*
-	 * If this is the last controller to be released, destroy the
-	 * shpchpd work queue
-	 */
-	if (atomic_dec_and_test(&shpchp_num_controllers))
-		destroy_workqueue(shpchp_wq);
 }
 
 static int hpc_power_on_slot(struct slot * slot)
@@ -1077,9 +1068,8 @@ int shpc_init(struct controller *ctrl, struct pci_dev *pdev)
 
 		rc = request_irq(ctrl->pci_dev->irq, shpc_isr, IRQF_SHARED,
 				 MY_NAME, (void *)ctrl);
-		ctrl_dbg(ctrl, "request_irq %d for hpc%d (returns %d)\n",
-			 ctrl->pci_dev->irq,
-		    atomic_read(&shpchp_num_controllers), rc);
+		ctrl_dbg(ctrl, "request_irq %d (returns %d)\n",
+			 ctrl->pci_dev->irq, rc);
 		if (rc) {
 			ctrl_err(ctrl, "Can't get irq %d for the hotplug "
 				 "controller\n", ctrl->pci_dev->irq);
@@ -1091,18 +1081,6 @@ int shpc_init(struct controller *ctrl, struct pci_dev *pdev)
 	shpc_get_max_bus_speed(ctrl);
 	shpc_get_cur_bus_speed(ctrl);
 
-	/*
-	 * If this is the first controller to be initialized,
-	 * initialize the shpchpd work queue
-	 */
-	if (atomic_add_return(1, &shpchp_num_controllers) == 1) {
-		shpchp_wq = create_singlethread_workqueue("shpchpd");
-		if (!shpchp_wq) {
-			rc = -ENOMEM;
-			goto abort_iounmap;
-		}
-	}
-
 	/*
 	 * Unmask all event interrupts of all slots
 	 */