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
diff --git a/Documentation/workqueue.txt b/Documentation/workqueue.txt
index e4498a2..996a27d 100644
--- a/Documentation/workqueue.txt
+++ b/Documentation/workqueue.txt
@@ -196,11 +196,11 @@
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
@@ -356,11 +356,11 @@
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.
@@ -368,12 +368,13 @@
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
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 14d18bf..d05387d 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -3335,7 +3335,7 @@
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;
diff --git a/drivers/isdn/hardware/eicon/divasmain.c b/drivers/isdn/hardware/eicon/divasmain.c
index ed9c555..f332b60 100644
--- a/drivers/isdn/hardware/eicon/divasmain.c
+++ b/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 *mem;
tasklet_kill(&pdpc->divas_task);
- flush_scheduled_work();
mem = psoft_isr->object;
psoft_isr->object = NULL;
diva_os_free(0, mem);
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 73d5139..838f571 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/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_debug;
extern int pciehp_force;
extern struct workqueue_struct *pciehp_wq;
+extern struct workqueue_struct *pciehp_ordered_wq;
#define dbg(format, arg...) \
do { \
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index aa5f3ff..7ac8358 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -43,6 +43,7 @@
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 @@
{
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");
}
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
index 8f58148..085dbb5 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/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 @@
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 @@
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 @@
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 @@
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)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 0cd4204..50a23da 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/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 @@
{
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 @@
/* 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 @@
{
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);
}
diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index d2627e1..e0c90e6 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/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_time;
extern int shpchp_debug;
extern struct workqueue_struct *shpchp_wq;
+extern struct workqueue_struct *shpchp_ordered_wq;
#define dbg(format, arg...) \
do { \
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index a7bd504..aca972b 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -33,7 +33,6 @@
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pci.h>
-#include <linux/workqueue.h>
#include "shpchp.h"
/* Global variables */
@@ -41,6 +40,7 @@
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 @@
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);
}
}
@@ -360,9 +360,23 @@
{
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;
}
@@ -370,6 +384,8 @@
{
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");
}
diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index 3387fbf..b00b09b 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/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 @@
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 @@
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 @@
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:
diff --git a/drivers/pci/hotplug/shpchp_hpc.c b/drivers/pci/hotplug/shpchp_hpc.c
index d3985e7..36547f0 100644
--- a/drivers/pci/hotplug/shpchp_hpc.c
+++ b/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 @@
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 @@
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);
@@ -1092,18 +1082,6 @@
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
*/
for (hp_slot = 0; hp_slot < ctrl->num_slots; hp_slot++) {
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index d7eb1e2..ebef7ab 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -144,7 +144,7 @@
error = -ENOMEM;
gfs_recovery_wq = alloc_workqueue("gfs_recovery",
- WQ_RESCUER | WQ_FREEZEABLE, 0);
+ WQ_MEM_RECLAIM | WQ_FREEZEABLE, 0);
if (!gfs_recovery_wq)
goto fail_wq;
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 1846a0d..f3ccaec 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1921,7 +1921,7 @@
goto out;
xfslogd_workqueue = alloc_workqueue("xfslogd",
- WQ_RESCUER | WQ_HIGHPRI, 1);
+ WQ_MEM_RECLAIM | WQ_HIGHPRI, 1);
if (!xfslogd_workqueue)
goto out_free_buf_zone;
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 25e02c9..070bb7a 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -243,11 +243,12 @@
WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */
WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
WQ_FREEZEABLE = 1 << 2, /* freeze during suspend */
- WQ_RESCUER = 1 << 3, /* has an rescue worker */
+ WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
WQ_HIGHPRI = 1 << 4, /* high priority */
WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */
WQ_DYING = 1 << 6, /* internal: workqueue is dying */
+ WQ_RESCUER = 1 << 7, /* internal: workqueue has rescuer */
WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
@@ -306,12 +307,30 @@
__alloc_workqueue_key((name), (flags), (max_active), NULL, NULL)
#endif
+/**
+ * alloc_ordered_workqueue - allocate an ordered workqueue
+ * @name: name of the workqueue
+ * @flags: WQ_* flags (only WQ_FREEZEABLE and WQ_MEM_RECLAIM are meaningful)
+ *
+ * Allocate an ordered workqueue. An ordered workqueue executes at
+ * most one work item at any given time in the queued order. They are
+ * implemented as unbound workqueues with @max_active of one.
+ *
+ * RETURNS:
+ * Pointer to the allocated workqueue on success, %NULL on failure.
+ */
+static inline struct workqueue_struct *
+alloc_ordered_workqueue(const char *name, unsigned int flags)
+{
+ return alloc_workqueue(name, WQ_UNBOUND | flags, 1);
+}
+
#define create_workqueue(name) \
- alloc_workqueue((name), WQ_RESCUER, 1)
+ alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
#define create_freezeable_workqueue(name) \
- alloc_workqueue((name), WQ_FREEZEABLE | WQ_UNBOUND | WQ_RESCUER, 1)
+ alloc_workqueue((name), WQ_FREEZEABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
#define create_singlethread_workqueue(name) \
- alloc_workqueue((name), WQ_UNBOUND | WQ_RESCUER, 1)
+ alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
extern void destroy_workqueue(struct workqueue_struct *wq);
@@ -325,7 +344,6 @@
extern void flush_workqueue(struct workqueue_struct *wq);
extern void flush_scheduled_work(void);
-extern void flush_delayed_work(struct delayed_work *work);
extern int schedule_work(struct work_struct *work);
extern int schedule_work_on(int cpu, struct work_struct *work);
@@ -337,8 +355,13 @@
int execute_in_process_context(work_func_t fn, struct execute_work *);
-extern int flush_work(struct work_struct *work);
-extern int cancel_work_sync(struct work_struct *work);
+extern bool flush_work(struct work_struct *work);
+extern bool flush_work_sync(struct work_struct *work);
+extern bool cancel_work_sync(struct work_struct *work);
+
+extern bool flush_delayed_work(struct delayed_work *dwork);
+extern bool flush_delayed_work_sync(struct delayed_work *work);
+extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
extern void workqueue_set_max_active(struct workqueue_struct *wq,
int max_active);
@@ -352,9 +375,9 @@
* it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
* cancel_work_sync() to wait on it.
*/
-static inline int cancel_delayed_work(struct delayed_work *work)
+static inline bool cancel_delayed_work(struct delayed_work *work)
{
- int ret;
+ bool ret;
ret = del_timer_sync(&work->timer);
if (ret)
@@ -367,9 +390,9 @@
* if it returns 0 the timer function may be running and the queueing is in
* progress.
*/
-static inline int __cancel_delayed_work(struct delayed_work *work)
+static inline bool __cancel_delayed_work(struct delayed_work *work)
{
- int ret;
+ bool ret;
ret = del_timer(&work->timer);
if (ret)
@@ -377,8 +400,6 @@
return ret;
}
-extern int cancel_delayed_work_sync(struct delayed_work *work);
-
/* Obsolete. use cancel_delayed_work_sync() */
static inline
void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
@@ -409,8 +430,4 @@
extern void thaw_workqueues(void);
#endif /* CONFIG_FREEZER */
-#ifdef CONFIG_LOCKDEP
-int in_workqueue_context(struct workqueue_struct *wq);
-#endif
-
#endif
diff --git a/include/trace/events/workqueue.h b/include/trace/events/workqueue.h
index 49682d7..7d49729 100644
--- a/include/trace/events/workqueue.h
+++ b/include/trace/events/workqueue.h
@@ -7,6 +7,76 @@
#include <linux/tracepoint.h>
#include <linux/workqueue.h>
+DECLARE_EVENT_CLASS(workqueue_work,
+
+ TP_PROTO(struct work_struct *work),
+
+ TP_ARGS(work),
+
+ TP_STRUCT__entry(
+ __field( void *, work )
+ ),
+
+ TP_fast_assign(
+ __entry->work = work;
+ ),
+
+ TP_printk("work struct %p", __entry->work)
+);
+
+/**
+ * workqueue_queue_work - called when a work gets queued
+ * @req_cpu: the requested cpu
+ * @cwq: pointer to struct cpu_workqueue_struct
+ * @work: pointer to struct work_struct
+ *
+ * This event occurs when a work is queued immediately or once a
+ * delayed work is actually queued on a workqueue (ie: once the delay
+ * has been reached).
+ */
+TRACE_EVENT(workqueue_queue_work,
+
+ TP_PROTO(unsigned int req_cpu, struct cpu_workqueue_struct *cwq,
+ struct work_struct *work),
+
+ TP_ARGS(req_cpu, cwq, work),
+
+ TP_STRUCT__entry(
+ __field( void *, work )
+ __field( void *, function)
+ __field( void *, workqueue)
+ __field( unsigned int, req_cpu )
+ __field( unsigned int, cpu )
+ ),
+
+ TP_fast_assign(
+ __entry->work = work;
+ __entry->function = work->func;
+ __entry->workqueue = cwq->wq;
+ __entry->req_cpu = req_cpu;
+ __entry->cpu = cwq->gcwq->cpu;
+ ),
+
+ TP_printk("work struct=%p function=%pf workqueue=%p req_cpu=%u cpu=%u",
+ __entry->work, __entry->function, __entry->workqueue,
+ __entry->req_cpu, __entry->cpu)
+);
+
+/**
+ * workqueue_activate_work - called when a work gets activated
+ * @work: pointer to struct work_struct
+ *
+ * This event occurs when a queued work is put on the active queue,
+ * which happens immediately after queueing unless @max_active limit
+ * is reached.
+ */
+DEFINE_EVENT(workqueue_work, workqueue_activate_work,
+
+ TP_PROTO(struct work_struct *work),
+
+ TP_ARGS(work)
+);
+
/**
* workqueue_execute_start - called immediately before the workqueue callback
* @work: pointer to struct work_struct
@@ -38,24 +108,13 @@
*
* Allows to track workqueue execution.
*/
-TRACE_EVENT(workqueue_execute_end,
+DEFINE_EVENT(workqueue_work, workqueue_execute_end,
TP_PROTO(struct work_struct *work),
- TP_ARGS(work),
-
- TP_STRUCT__entry(
- __field( void *, work )
- ),
-
- TP_fast_assign(
- __entry->work = work;
- ),
-
- TP_printk("work struct %p", __entry->work)
+ TP_ARGS(work)
);
-
#endif /* _TRACE_WORKQUEUE_H */
/* This part must be outside protection */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f77afd9..30acdb7 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -42,9 +42,6 @@
#include <linux/lockdep.h>
#include <linux/idr.h>
-#define CREATE_TRACE_POINTS
-#include <trace/events/workqueue.h>
-
#include "workqueue_sched.h"
enum {
@@ -257,6 +254,9 @@
EXPORT_SYMBOL_GPL(system_nrt_wq);
EXPORT_SYMBOL_GPL(system_unbound_wq);
+#define CREATE_TRACE_POINTS
+#include <trace/events/workqueue.h>
+
#define for_each_busy_worker(worker, i, pos, gcwq) \
for (i = 0; i < BUSY_WORKER_HASH_SIZE; i++) \
hlist_for_each_entry(worker, pos, &gcwq->busy_hash[i], hentry)
@@ -310,21 +310,6 @@
(cpu) < WORK_CPU_NONE; \
(cpu) = __next_wq_cpu((cpu), cpu_possible_mask, (wq)))
-#ifdef CONFIG_LOCKDEP
-/**
- * in_workqueue_context() - in context of specified workqueue?
- * @wq: the workqueue of interest
- *
- * Checks lockdep state to see if the current task is executing from
- * within a workqueue item. This function exists only if lockdep is
- * enabled.
- */
-int in_workqueue_context(struct workqueue_struct *wq)
-{
- return lock_is_held(&wq->lockdep_map);
-}
-#endif
-
#ifdef CONFIG_DEBUG_OBJECTS_WORK
static struct debug_obj_descr work_debug_descr;
@@ -604,7 +589,9 @@
{
atomic_t *nr_running = get_gcwq_nr_running(gcwq->cpu);
- return !list_empty(&gcwq->worklist) && atomic_read(nr_running) <= 1;
+ return !list_empty(&gcwq->worklist) &&
+ (atomic_read(nr_running) <= 1 ||
+ gcwq->flags & GCWQ_HIGHPRI_PENDING);
}
/* Do we need a new worker? Called from manager. */
@@ -997,6 +984,7 @@
/* gcwq determined, get cwq and queue */
cwq = get_cwq(gcwq->cpu, wq);
+ trace_workqueue_queue_work(cpu, cwq, work);
BUG_ON(!list_empty(&work->entry));
@@ -1004,6 +992,7 @@
work_flags = work_color_to_flags(cwq->work_color);
if (likely(cwq->nr_active < cwq->max_active)) {
+ trace_workqueue_activate_work(work);
cwq->nr_active++;
worklist = gcwq_determine_ins_pos(gcwq, cwq);
} else {
@@ -1679,6 +1668,7 @@
struct work_struct, entry);
struct list_head *pos = gcwq_determine_ins_pos(cwq->gcwq, cwq);
+ trace_workqueue_activate_work(work);
move_linked_works(work, pos, NULL);
__clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work));
cwq->nr_active++;
@@ -2326,27 +2316,17 @@
}
EXPORT_SYMBOL_GPL(flush_workqueue);
-/**
- * flush_work - block until a work_struct's callback has terminated
- * @work: the work which is to be flushed
- *
- * Returns false if @work has already terminated.
- *
- * It is expected that, prior to calling flush_work(), the caller has
- * arranged for the work to not be requeued, otherwise it doesn't make
- * sense to use this function.
- */
-int flush_work(struct work_struct *work)
+static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr,
+ bool wait_executing)
{
struct worker *worker = NULL;
struct global_cwq *gcwq;
struct cpu_workqueue_struct *cwq;
- struct wq_barrier barr;
might_sleep();
gcwq = get_work_gcwq(work);
if (!gcwq)
- return 0;
+ return false;
spin_lock_irq(&gcwq->lock);
if (!list_empty(&work->entry)) {
@@ -2359,28 +2339,127 @@
cwq = get_work_cwq(work);
if (unlikely(!cwq || gcwq != cwq->gcwq))
goto already_gone;
- } else {
+ } else if (wait_executing) {
worker = find_worker_executing_work(gcwq, work);
if (!worker)
goto already_gone;
cwq = worker->current_cwq;
- }
+ } else
+ goto already_gone;
- insert_wq_barrier(cwq, &barr, work, worker);
+ insert_wq_barrier(cwq, barr, work, worker);
spin_unlock_irq(&gcwq->lock);
lock_map_acquire(&cwq->wq->lockdep_map);
lock_map_release(&cwq->wq->lockdep_map);
-
- wait_for_completion(&barr.done);
- destroy_work_on_stack(&barr.work);
- return 1;
+ return true;
already_gone:
spin_unlock_irq(&gcwq->lock);
- return 0;
+ return false;
+}
+
+/**
+ * flush_work - wait for a work to finish executing the last queueing instance
+ * @work: the work to flush
+ *
+ * Wait until @work has finished execution. This function considers
+ * only the last queueing instance of @work. If @work has been
+ * enqueued across different CPUs on a non-reentrant workqueue or on
+ * multiple workqueues, @work might still be executing on return on
+ * some of the CPUs from earlier queueing.
+ *
+ * If @work was queued only on a non-reentrant, ordered or unbound
+ * workqueue, @work is guaranteed to be idle on return if it hasn't
+ * been requeued since flush started.
+ *
+ * RETURNS:
+ * %true if flush_work() waited for the work to finish execution,
+ * %false if it was already idle.
+ */
+bool flush_work(struct work_struct *work)
+{
+ struct wq_barrier barr;
+
+ if (start_flush_work(work, &barr, true)) {
+ wait_for_completion(&barr.done);
+ destroy_work_on_stack(&barr.work);
+ return true;
+ } else
+ return false;
}
EXPORT_SYMBOL_GPL(flush_work);
+static bool wait_on_cpu_work(struct global_cwq *gcwq, struct work_struct *work)
+{
+ struct wq_barrier barr;
+ struct worker *worker;
+
+ spin_lock_irq(&gcwq->lock);
+
+ worker = find_worker_executing_work(gcwq, work);
+ if (unlikely(worker))
+ insert_wq_barrier(worker->current_cwq, &barr, work, worker);
+
+ spin_unlock_irq(&gcwq->lock);
+
+ if (unlikely(worker)) {
+ wait_for_completion(&barr.done);
+ destroy_work_on_stack(&barr.work);
+ return true;
+ } else
+ return false;
+}
+
+static bool wait_on_work(struct work_struct *work)
+{
+ bool ret = false;
+ int cpu;
+
+ might_sleep();
+
+ lock_map_acquire(&work->lockdep_map);
+ lock_map_release(&work->lockdep_map);
+
+ for_each_gcwq_cpu(cpu)
+ ret |= wait_on_cpu_work(get_gcwq(cpu), work);
+ return ret;
+}
+
+/**
+ * flush_work_sync - wait until a work has finished execution
+ * @work: the work to flush
+ *
+ * Wait until @work has finished execution. On return, it's
+ * guaranteed that all queueing instances of @work which happened
+ * before this function is called are finished. In other words, if
+ * @work hasn't been requeued since this function was called, @work is
+ * guaranteed to be idle on return.
+ *
+ * RETURNS:
+ * %true if flush_work_sync() waited for the work to finish execution,
+ * %false if it was already idle.
+ */
+bool flush_work_sync(struct work_struct *work)
+{
+ struct wq_barrier barr;
+ bool pending, waited;
+
+ /* we'll wait for executions separately, queue barr only if pending */
+ pending = start_flush_work(work, &barr, false);
+
+ /* wait for executions to finish */
+ waited = wait_on_work(work);
+
+ /* wait for the pending one */
+ if (pending) {
+ wait_for_completion(&barr.done);
+ destroy_work_on_stack(&barr.work);
+ }
+
+ return pending || waited;
+}
+EXPORT_SYMBOL_GPL(flush_work_sync);
+
/*
* Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit,
* so this work can't be re-armed in any way.
@@ -2423,39 +2502,7 @@
return ret;
}
-static void wait_on_cpu_work(struct global_cwq *gcwq, struct work_struct *work)
-{
- struct wq_barrier barr;
- struct worker *worker;
-
- spin_lock_irq(&gcwq->lock);
-
- worker = find_worker_executing_work(gcwq, work);
- if (unlikely(worker))
- insert_wq_barrier(worker->current_cwq, &barr, work, worker);
-
- spin_unlock_irq(&gcwq->lock);
-
- if (unlikely(worker)) {
- wait_for_completion(&barr.done);
- destroy_work_on_stack(&barr.work);
- }
-}
-
-static void wait_on_work(struct work_struct *work)
-{
- int cpu;
-
- might_sleep();
-
- lock_map_acquire(&work->lockdep_map);
- lock_map_release(&work->lockdep_map);
-
- for_each_gcwq_cpu(cpu)
- wait_on_cpu_work(get_gcwq(cpu), work);
-}
-
-static int __cancel_work_timer(struct work_struct *work,
+static bool __cancel_work_timer(struct work_struct *work,
struct timer_list* timer)
{
int ret;
@@ -2472,42 +2519,81 @@
}
/**
- * cancel_work_sync - block until a work_struct's callback has terminated
- * @work: the work which is to be flushed
+ * cancel_work_sync - cancel a work and wait for it to finish
+ * @work: the work to cancel
*
- * Returns true if @work was pending.
+ * Cancel @work and wait for its execution to finish. This function
+ * can be used even if the work re-queues itself or migrates to
+ * another workqueue. On return from this function, @work is
+ * guaranteed to be not pending or executing on any CPU.
*
- * cancel_work_sync() will cancel the work if it is queued. If the work's
- * callback appears to be running, cancel_work_sync() will block until it
- * has completed.
+ * cancel_work_sync(&delayed_work->work) must not be used for
+ * delayed_work's. Use cancel_delayed_work_sync() instead.
*
- * It is possible to use this function if the work re-queues itself. It can
- * cancel the work even if it migrates to another workqueue, however in that
- * case it only guarantees that work->func() has completed on the last queued
- * workqueue.
- *
- * cancel_work_sync(&delayed_work->work) should be used only if ->timer is not
- * pending, otherwise it goes into a busy-wait loop until the timer expires.
- *
- * The caller must ensure that workqueue_struct on which this work was last
+ * The caller must ensure that the workqueue on which @work was last
* queued can't be destroyed before this function returns.
+ *
+ * RETURNS:
+ * %true if @work was pending, %false otherwise.
*/
-int cancel_work_sync(struct work_struct *work)
+bool cancel_work_sync(struct work_struct *work)
{
return __cancel_work_timer(work, NULL);
}
EXPORT_SYMBOL_GPL(cancel_work_sync);
/**
- * cancel_delayed_work_sync - reliably kill off a delayed work.
- * @dwork: the delayed work struct
+ * flush_delayed_work - wait for a dwork to finish executing the last queueing
+ * @dwork: the delayed work to flush
*
- * Returns true if @dwork was pending.
+ * Delayed timer is cancelled and the pending work is queued for
+ * immediate execution. Like flush_work(), this function only
+ * considers the last queueing instance of @dwork.
*
- * It is possible to use this function if @dwork rearms itself via queue_work()
- * or queue_delayed_work(). See also the comment for cancel_work_sync().
+ * RETURNS:
+ * %true if flush_work() waited for the work to finish execution,
+ * %false if it was already idle.
*/
-int cancel_delayed_work_sync(struct delayed_work *dwork)
+bool flush_delayed_work(struct delayed_work *dwork)
+{
+ if (del_timer_sync(&dwork->timer))
+ __queue_work(raw_smp_processor_id(),
+ get_work_cwq(&dwork->work)->wq, &dwork->work);
+ return flush_work(&dwork->work);
+}
+EXPORT_SYMBOL(flush_delayed_work);
+
+/**
+ * flush_delayed_work_sync - wait for a dwork to finish
+ * @dwork: the delayed work to flush
+ *
+ * Delayed timer is cancelled and the pending work is queued for
+ * execution immediately. Other than timer handling, its behavior
+ * is identical to flush_work_sync().
+ *
+ * RETURNS:
+ * %true if flush_work_sync() waited for the work to finish execution,
+ * %false if it was already idle.
+ */
+bool flush_delayed_work_sync(struct delayed_work *dwork)
+{
+ if (del_timer_sync(&dwork->timer))
+ __queue_work(raw_smp_processor_id(),
+ get_work_cwq(&dwork->work)->wq, &dwork->work);
+ return flush_work_sync(&dwork->work);
+}
+EXPORT_SYMBOL(flush_delayed_work_sync);
+
+/**
+ * cancel_delayed_work_sync - cancel a delayed work and wait for it to finish
+ * @dwork: the delayed work cancel
+ *
+ * This is cancel_work_sync() for delayed works.
+ *
+ * RETURNS:
+ * %true if @dwork was pending, %false otherwise.
+ */
+bool cancel_delayed_work_sync(struct delayed_work *dwork)
{
return __cancel_work_timer(&dwork->work, &dwork->timer);
}
@@ -2559,23 +2645,6 @@
EXPORT_SYMBOL(schedule_delayed_work);
/**
- * flush_delayed_work - block until a dwork_struct's callback has terminated
- * @dwork: the delayed work which is to be flushed
- *
- * Any timeout is cancelled, and any pending work is run immediately.
- */
-void flush_delayed_work(struct delayed_work *dwork)
-{
- if (del_timer_sync(&dwork->timer)) {
- __queue_work(get_cpu(), get_work_cwq(&dwork->work)->wq,
- &dwork->work);
- put_cpu();
- }
- flush_work(&dwork->work);
-}
-EXPORT_SYMBOL(flush_delayed_work);
-
-/**
* schedule_delayed_work_on - queue work in global workqueue on CPU after delay
* @cpu: cpu to use
* @dwork: job to be done
@@ -2592,13 +2661,15 @@
EXPORT_SYMBOL(schedule_delayed_work_on);
/**
- * schedule_on_each_cpu - call a function on each online CPU from keventd
+ * schedule_on_each_cpu - execute a function synchronously on each online CPU
* @func: the function to call
*
- * Returns zero on success.
- * Returns -ve errno on failure.
- *
+ * schedule_on_each_cpu() executes @func on each online CPU using the
+ * system workqueue and blocks until all CPUs have completed.
* schedule_on_each_cpu() is very slow.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
*/
int schedule_on_each_cpu(work_func_t func)
{
@@ -2764,6 +2835,13 @@
unsigned int cpu;
/*
+ * Workqueues which may be used during memory reclaim should
+ * have a rescuer to guarantee forward progress.
+ */
+ if (flags & WQ_MEM_RECLAIM)
+ flags |= WQ_RESCUER;
+
+ /*
* Unbound workqueues aren't concurrency managed and should be
* dispatched to workers immediately.
*/
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index dd186c1..d4e940a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -840,7 +840,6 @@
ret = 0;
if (drain) {
lru_add_drain_all();
- flush_scheduled_work();
cond_resched();
drain_all_pages();
}
@@ -862,7 +861,6 @@
}
/* drain all zone's lru pagevec, this is asyncronous... */
lru_add_drain_all();
- flush_scheduled_work();
yield();
/* drain pcp pages , this is synchrouns. */
drain_all_pages();