diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/ata/libata-core.c | 96 | ||||
| -rw-r--r-- | drivers/scsi/scsi_scan.c | 3 | ||||
| -rw-r--r-- | drivers/scsi/sd.c | 109 | ||||
| -rw-r--r-- | fs/inode.c | 20 | ||||
| -rw-r--r-- | fs/super.c | 10 | ||||
| -rw-r--r-- | include/linux/async.h | 25 | ||||
| -rw-r--r-- | include/linux/fs.h | 5 | ||||
| -rw-r--r-- | init/do_mounts.c | 2 | ||||
| -rw-r--r-- | init/main.c | 5 | ||||
| -rw-r--r-- | kernel/Makefile | 3 | ||||
| -rw-r--r-- | kernel/async.c | 321 | ||||
| -rw-r--r-- | kernel/irq/autoprobe.c | 5 | ||||
| -rw-r--r-- | kernel/module.c | 2 |
13 files changed, 510 insertions, 96 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index fecca4223f8e..f178a450ec08 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -56,6 +56,7 @@ #include <linux/workqueue.h> #include <linux/scatterlist.h> #include <linux/io.h> +#include <linux/async.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_host.h> @@ -5909,6 +5910,54 @@ void ata_host_init(struct ata_host *host, struct device *dev, host->ops = ops; } + +static void async_port_probe(void *data, async_cookie_t cookie) +{ + int rc; + struct ata_port *ap = data; + /* probe */ + if (ap->ops->error_handler) { + struct ata_eh_info *ehi = &ap->link.eh_info; + unsigned long flags; + + ata_port_probe(ap); + + /* kick EH for boot probing */ + spin_lock_irqsave(ap->lock, flags); + + ehi->probe_mask |= ATA_ALL_DEVICES; + ehi->action |= ATA_EH_RESET | ATA_EH_LPM; + ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET; + + ap->pflags &= ~ATA_PFLAG_INITIALIZING; + ap->pflags |= ATA_PFLAG_LOADING; + ata_port_schedule_eh(ap); + + spin_unlock_irqrestore(ap->lock, flags); + + /* wait for EH to finish */ + ata_port_wait_eh(ap); + } else { + DPRINTK("ata%u: bus probe begin\n", ap->print_id); + rc = ata_bus_probe(ap); + DPRINTK("ata%u: bus probe end\n", ap->print_id); + + if (rc) { + /* FIXME: do something useful here? + * Current libata behavior will + * tear down everything when + * the module is removed + * or the h/w is unplugged. + */ + } + } + + /* in order to keep device order, we need to synchronize at this point */ + async_synchronize_cookie(cookie); + + ata_scsi_scan_host(ap, 1); + +} /** * ata_host_register - register initialized ATA host * @host: ATA host to register @@ -5988,52 +6037,9 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht) DPRINTK("probe begin\n"); for (i = 0; i < host->n_ports; i++) { struct ata_port *ap = host->ports[i]; - - /* probe */ - if (ap->ops->error_handler) { - struct ata_eh_info *ehi = &ap->link.eh_info; - unsigned long flags; - - ata_port_probe(ap); - - /* kick EH for boot probing */ - spin_lock_irqsave(ap->lock, flags); - - ehi->probe_mask |= ATA_ALL_DEVICES; - ehi->action |= ATA_EH_RESET | ATA_EH_LPM; - ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET; - - ap->pflags &= ~ATA_PFLAG_INITIALIZING; - ap->pflags |= ATA_PFLAG_LOADING; - ata_port_schedule_eh(ap); - - spin_unlock_irqrestore(ap->lock, flags); - - /* wait for EH to finish */ - ata_port_wait_eh(ap); - } else { - DPRINTK("ata%u: bus probe begin\n", ap->print_id); - rc = ata_bus_probe(ap); - DPRINTK("ata%u: bus probe end\n", ap->print_id); - - if (rc) { - /* FIXME: do something useful here? - * Current libata behavior will - * tear down everything when - * the module is removed - * or the h/w is unplugged. - */ - } - } - } - - /* probes are done, now scan each port's disk(s) */ - DPRINTK("host probe begin\n"); - for (i = 0; i < host->n_ports; i++) { - struct ata_port *ap = host->ports[i]; - - ata_scsi_scan_host(ap, 1); + async_schedule(async_port_probe, ap); } + DPRINTK("probe end\n"); return 0; } diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 18486b51668d..17914a346f71 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -32,6 +32,7 @@ #include <linux/delay.h> #include <linux/kthread.h> #include <linux/spinlock.h> +#include <linux/async.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -179,6 +180,8 @@ int scsi_complete_async_scans(void) spin_unlock(&async_scan_lock); kfree(data); + /* Synchronize async operations globally */ + async_synchronize_full(); return 0; } diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 62b28d58e65e..e035c1114010 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -48,6 +48,7 @@ #include <linux/delay.h> #include <linux/mutex.h> #include <linux/string_helpers.h> +#include <linux/async.h> #include <asm/uaccess.h> #include <scsi/scsi.h> @@ -1802,6 +1803,71 @@ static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen) return 0; } +/* + * The asynchronous part of sd_probe + */ +static void sd_probe_async(void *data, async_cookie_t cookie) +{ + struct scsi_disk *sdkp = data; + struct scsi_device *sdp; + struct gendisk *gd; + u32 index; + struct device *dev; + + sdp = sdkp->device; + gd = sdkp->disk; + index = sdkp->index; + dev = &sdp->sdev_gendev; + + if (!sdp->request_queue->rq_timeout) { + if (sdp->type != TYPE_MOD) + blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT); + else + blk_queue_rq_timeout(sdp->request_queue, + SD_MOD_TIMEOUT); + } + + device_initialize(&sdkp->dev); + sdkp->dev.parent = &sdp->sdev_gendev; + sdkp->dev.class = &sd_disk_class; + strncpy(sdkp->dev.bus_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE); + + if (device_add(&sdkp->dev)) + goto out_free_index; + + get_device(&sdp->sdev_gendev); + + if (index < SD_MAX_DISKS) { + gd->major = sd_major((index & 0xf0) >> 4); + gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); + gd->minors = SD_MINORS; + } + gd->fops = &sd_fops; + gd->private_data = &sdkp->driver; + gd->queue = sdkp->device->request_queue; + + sd_revalidate_disk(gd); + + blk_queue_prep_rq(sdp->request_queue, sd_prep_fn); + + gd->driverfs_dev = &sdp->sdev_gendev; + gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS; + if (sdp->removable) + gd->flags |= GENHD_FL_REMOVABLE; + + dev_set_drvdata(dev, sdkp); + add_disk(gd); + sd_dif_config_host(sdkp); + + sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n", + sdp->removable ? "removable " : ""); + + return; + + out_free_index: + ida_remove(&sd_index_ida, index); +} + /** * sd_probe - called during driver initialization and whenever a * new scsi device is attached to the system. It is called once @@ -1865,48 +1931,7 @@ static int sd_probe(struct device *dev) sdkp->openers = 0; sdkp->previous_state = 1; - if (!sdp->request_queue->rq_timeout) { - if (sdp->type != TYPE_MOD) - blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT); - else - blk_queue_rq_timeout(sdp->request_queue, - SD_MOD_TIMEOUT); - } - - device_initialize(&sdkp->dev); - sdkp->dev.parent = &sdp->sdev_gendev; - sdkp->dev.class = &sd_disk_class; - strncpy(sdkp->dev.bus_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE); - - if (device_add(&sdkp->dev)) - goto out_free_index; - - get_device(&sdp->sdev_gendev); - - if (index < SD_MAX_DISKS) { - gd->major = sd_major((index & 0xf0) >> 4); - gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); - gd->minors = SD_MINORS; - } - gd->fops = &sd_fops; - gd->private_data = &sdkp->driver; - gd->queue = sdkp->device->request_queue; - - sd_revalidate_disk(gd); - - blk_queue_prep_rq(sdp->request_queue, sd_prep_fn); - - gd->driverfs_dev = &sdp->sdev_gendev; - gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS; - if (sdp->removable) - gd->flags |= GENHD_FL_REMOVABLE; - - dev_set_drvdata(dev, sdkp); - add_disk(gd); - sd_dif_config_host(sdkp); - - sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n", - sdp->removable ? "removable " : ""); + async_schedule(sd_probe_async, sdkp); return 0; diff --git a/fs/inode.c b/fs/inode.c index 7a6e8c2ff7b1..0013ac1af8e7 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -22,6 +22,7 @@ #include <linux/bootmem.h> #include <linux/inotify.h> #include <linux/mount.h> +#include <linux/async.h> /* * This is needed for the following functions: @@ -1138,16 +1139,11 @@ EXPORT_SYMBOL(remove_inode_hash); * I_FREEING is set so that no-one will take a new reference to the inode while * it is being deleted. */ -void generic_delete_inode(struct inode *inode) +static void generic_delete_inode_async(void *data, async_cookie_t cookie) { + struct inode *inode = data; const struct super_operations *op = inode->i_sb->s_op; - list_del_init(&inode->i_list); - list_del_init(&inode->i_sb_list); - inode->i_state |= I_FREEING; - inodes_stat.nr_inodes--; - spin_unlock(&inode_lock); - security_inode_delete(inode); if (op->delete_inode) { @@ -1171,6 +1167,16 @@ void generic_delete_inode(struct inode *inode) destroy_inode(inode); } +void generic_delete_inode(struct inode *inode) +{ + list_del_init(&inode->i_list); + list_del_init(&inode->i_sb_list); + inode->i_state |= I_FREEING; + inodes_stat.nr_inodes--; + spin_unlock(&inode_lock); + async_schedule_special(generic_delete_inode_async, inode, &inode->i_sb->s_async_list); +} + EXPORT_SYMBOL(generic_delete_inode); static void generic_forget_inode(struct inode *inode) diff --git a/fs/super.c b/fs/super.c index ddba069d7a99..cb20744ec789 100644 --- a/fs/super.c +++ b/fs/super.c @@ -38,6 +38,7 @@ #include <linux/kobject.h> #include <linux/mutex.h> #include <linux/file.h> +#include <linux/async.h> #include <asm/uaccess.h> #include "internal.h" @@ -71,6 +72,7 @@ static struct super_block *alloc_super(struct file_system_type *type) INIT_HLIST_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); INIT_LIST_HEAD(&s->s_dentry_lru); + INIT_LIST_HEAD(&s->s_async_list); init_rwsem(&s->s_umount); mutex_init(&s->s_lock); lockdep_set_class(&s->s_umount, &type->s_umount_key); @@ -289,11 +291,18 @@ void generic_shutdown_super(struct super_block *sb) { const struct super_operations *sop = sb->s_op; + if (sb->s_root) { shrink_dcache_for_umount(sb); fsync_super(sb); lock_super(sb); sb->s_flags &= ~MS_ACTIVE; + + /* + * wait for asynchronous fs operations to finish before going further + */ + async_synchronize_full_special(&sb->s_async_list); + /* bad name - it should be evict_inodes() */ invalidate_inodes(sb); lock_kernel(); @@ -449,6 +458,7 @@ void sync_filesystems(int wait) if (sb->s_flags & MS_RDONLY) continue; sb->s_need_sync_fs = 1; + async_synchronize_full_special(&sb->s_async_list); } restart: diff --git a/include/linux/async.h b/include/linux/async.h new file mode 100644 index 000000000000..c4ecacd0b327 --- /dev/null +++ b/include/linux/async.h @@ -0,0 +1,25 @@ +/* + * async.h: Asynchronous function calls for boot performance + * + * (C) Copyright 2009 Intel Corporation + * Author: Arjan van de Ven <arjan@linux.intel.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include <linux/types.h> +#include <linux/list.h> + +typedef u64 async_cookie_t; +typedef void (async_func_ptr) (void *data, async_cookie_t cookie); + +extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data); +extern async_cookie_t async_schedule_special(async_func_ptr *ptr, void *data, struct list_head *list); +extern void async_synchronize_full(void); +extern void async_synchronize_full_special(struct list_head *list); +extern void async_synchronize_cookie(async_cookie_t cookie); +extern void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *list); + diff --git a/include/linux/fs.h b/include/linux/fs.h index d7eba77f666e..e38a64d71eff 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1184,6 +1184,11 @@ struct super_block { * generic_show_options() */ char *s_options; + + /* + * storage for asynchronous operations + */ + struct list_head s_async_list; }; extern struct timespec current_fs_time(struct super_block *sb); diff --git a/init/do_mounts.c b/init/do_mounts.c index 5efca73b39f9..708105e163df 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -13,6 +13,7 @@ #include <linux/init.h> #include <linux/fs.h> #include <linux/initrd.h> +#include <linux/async.h> #include <linux/nfs_fs.h> #include <linux/nfs_fs_sb.h> @@ -372,6 +373,7 @@ void __init prepare_namespace(void) /* wait for the known devices to complete their probing */ while (driver_probe_done() != 0) msleep(100); + async_synchronize_full(); md_run_setup(); diff --git a/init/main.c b/init/main.c index 05b313283311..844209453c02 100644 --- a/init/main.c +++ b/init/main.c @@ -62,6 +62,7 @@ #include <linux/signal.h> #include <linux/idr.h> #include <linux/ftrace.h> +#include <linux/async.h> #include <trace/boot.h> #include <asm/io.h> @@ -685,7 +686,7 @@ asmlinkage void __init start_kernel(void) rest_init(); } -static int initcall_debug; +int initcall_debug; core_param(initcall_debug, initcall_debug, bool, 0644); int do_one_initcall(initcall_t fn) @@ -786,6 +787,8 @@ static void run_init_process(char *init_filename) */ static noinline int init_post(void) { + /* need to finish all async __init code before freeing the memory */ + async_synchronize_full(); free_initmem(); unlock_kernel(); mark_rodata_ro(); diff --git a/kernel/Makefile b/kernel/Makefile index e1c5bf3365c0..2921d90ce32f 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -9,7 +9,8 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ - notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o + notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \ + async.o ifdef CONFIG_FUNCTION_TRACER # Do not trace debug files and internal ftrace files diff --git a/kernel/async.c b/kernel/async.c new file mode 100644 index 000000000000..97373380c9e7 --- /dev/null +++ b/kernel/async.c @@ -0,0 +1,321 @@ +/* + * async.c: Asynchronous function calls for boot performance + * + * (C) Copyright 2009 Intel Corporation + * Author: Arjan van de Ven <arjan@linux.intel.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + + +/* + +Goals and Theory of Operation + +The primary goal of this feature is to reduce the kernel boot time, +by doing various independent hardware delays and discovery operations +decoupled and not strictly serialized. + +More specifically, the asynchronous function call concept allows +certain operations (primarily during system boot) to happen +asynchronously, out of order, while these operations still +have their externally visible parts happen sequentially and in-order. +(not unlike how out-of-order CPUs retire their instructions in order) + +Key to the asynchronous function call implementation is the concept of +a "sequence cookie" (which, although it has an abstracted type, can be +thought of as a monotonically incrementing number). + +The async core will assign each scheduled event such a sequence cookie and +pass this to the called functions. + +The asynchronously called function should before doing a globally visible +operation, such as registering device numbers, call the +async_synchronize_cookie() function and pass in its own cookie. The +async_synchronize_cookie() function will make sure that all asynchronous +operations that were scheduled prior to the operation corresponding with the +cookie have completed. + +Subsystem/driver initialization code that scheduled asynchronous probe +functions, but which shares global resources with other drivers/subsystems +that do not use the asynchronous call feature, need to do a full +synchronization with the async_synchronize_full() function, before returning +from their init function. This is to maintain strict ordering between the +asynchronous and synchronous parts of the kernel. + +*/ + +#include <linux/async.h> +#include <linux/module.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/kthread.h> +#include <asm/atomic.h> + +static async_cookie_t next_cookie = 1; + +#define MAX_THREADS 256 +#define MAX_WORK 32768 + +static LIST_HEAD(async_pending); +static LIST_HEAD(async_running); +static DEFINE_SPINLOCK(async_lock); + +struct async_entry { + struct list_head list; + async_cookie_t cookie; + async_func_ptr *func; + void *data; + struct list_head *running; +}; + +static DECLARE_WAIT_QUEUE_HEAD(async_done); +static DECLARE_WAIT_QUEUE_HEAD(async_new); + +static atomic_t entry_count; +static atomic_t thread_count; + +extern int initcall_debug; + + +/* + * MUST be called with the lock held! + */ +static async_cookie_t __lowest_in_progress(struct list_head *running) +{ + struct async_entry *entry; + if (!list_empty(&async_pending)) { + entry = list_first_entry(&async_pending, + struct async_entry, list); + return entry->cookie; + } else if (!list_empty(running)) { + entry = list_first_entry(running, + struct async_entry, list); + return entry->cookie; + } else { + /* nothing in progress... next_cookie is "infinity" */ + return next_cookie; + } + +} +/* + * pick the first pending entry and run it + */ +static void run_one_entry(void) +{ + unsigned long flags; + struct async_entry *entry; + ktime_t calltime, delta, rettime; + + /* 1) pick one task from the pending queue */ + + spin_lock_irqsave(&async_lock, flags); + if (list_empty(&async_pending)) + goto out; + entry = list_first_entry(&async_pending, struct async_entry, list); + + /* 2) move it to the running queue */ + list_del(&entry->list); + list_add_tail(&entry->list, &async_running); + spin_unlock_irqrestore(&async_lock, flags); + + /* 3) run it (and print duration)*/ + if (initcall_debug && system_state == SYSTEM_BOOTING) { + printk("calling %lli_%pF @ %i\n", entry->cookie, entry->func, task_pid_nr(current)); + calltime = ktime_get(); + } + entry->func(entry->data, entry->cookie); + if (initcall_debug && system_state == SYSTEM_BOOTING) { + rettime = ktime_get(); + delta = ktime_sub(rettime, calltime); + printk("initcall %lli_%pF returned 0 after %lld usecs\n", entry->cookie, + entry->func, ktime_to_ns(delta) >> 10); + } + + /* 4) remove it from the running queue */ + spin_lock_irqsave(&async_lock, flags); + list_del(&entry->list); + + /* 5) free the entry */ + kfree(entry); + atomic_dec(&entry_count); + + spin_unlock_irqrestore(&async_lock, flags); + + /* 6) wake up any waiters. */ + wake_up(&async_done); + return; + +out: + spin_unlock_irqrestore(&async_lock, flags); +} + + +static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct list_head *running) +{ + struct async_entry *entry; + unsigned long flags; + async_cookie_t newcookie; + + + /* allow irq-off callers */ + entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); + + /* + * If we're out of memory or if there's too much work + * pending already, we execute synchronously. + */ + if (!entry || atomic_read(&entry_count) > MAX_WORK) { + kfree(entry); + spin_lock_irqsave(&async_lock, flags); + newcookie = next_cookie++; + spin_unlock_irqrestore(&async_lock, flags); + + /* low on memory.. run synchronously */ + ptr(data, newcookie); + return newcookie; + } + entry->func = ptr; + entry->data = data; + entry->running = running; + + spin_lock_irqsave(&async_lock, flags); + newcookie = entry->cookie = next_cookie++; + list_add_tail(&entry->list, &async_pending); + atomic_inc(&entry_count); + spin_unlock_irqrestore(&async_lock, flags); + wake_up(&async_new); + return newcookie; +} + +async_cookie_t async_schedule(async_func_ptr *ptr, void *data) +{ + return __async_schedule(ptr, data, &async_pending); +} +EXPORT_SYMBOL_GPL(async_schedule); + +async_cookie_t async_schedule_special(async_func_ptr *ptr, void *data, struct list_head *running) +{ + return __async_schedule(ptr, data, running); +} +EXPORT_SYMBOL_GPL(async_schedule_special); + +void async_synchronize_full(void) +{ + async_synchronize_cookie(next_cookie); +} +EXPORT_SYMBOL_GPL(async_synchronize_full); + +void async_synchronize_full_special(struct list_head *list) +{ + async_synchronize_cookie_special(next_cookie, list); +} +EXPORT_SYMBOL_GPL(async_synchronize_full_special); + +void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *running) +{ + ktime_t starttime, delta, endtime; + + if (initcall_debug && system_state == SYSTEM_BOOTING) { + printk("async_waiting @ %i\n", task_pid_nr(current)); + starttime = ktime_get(); + } + + wait_event(async_done, __lowest_in_progress(running) >= cookie); + + if (initcall_debug && system_state == SYSTEM_BOOTING) { + endtime = ktime_get(); + delta = ktime_sub(endtime, starttime); + + printk("async_continuing @ %i after %lli usec\n", + task_pid_nr(current), ktime_to_ns(delta) >> 10); + } +} +EXPORT_SYMBOL_GPL(async_synchronize_cookie_special); + +void async_synchronize_cookie(async_cookie_t cookie) +{ + async_synchronize_cookie_special(cookie, &async_running); +} +EXPORT_SYMBOL_GPL(async_synchronize_cookie); + + +static int async_thread(void *unused) +{ + DECLARE_WAITQUEUE(wq, current); + add_wait_queue(&async_new, &wq); + + while (!kthread_should_stop()) { + int ret = HZ; + set_current_state(TASK_INTERRUPTIBLE); + /* + * check the list head without lock.. false positives + * are dealt with inside run_one_entry() while holding + * the lock. + */ + rmb(); + if (!list_empty(&async_pending)) + run_one_entry(); + else + ret = schedule_timeout(HZ); + + if (ret == 0) { + /* + * we timed out, this means we as thread are redundant. + * we sign off and die, but we to avoid any races there + * is a last-straw check to see if work snuck in. + */ + atomic_dec(&thread_count); + wmb(); /* manager must see our departure first */ + if (list_empty(&async_pending)) + break; + /* + * woops work came in between us timing out and us + * signing off; we need to stay alive and keep working. + */ + atomic_inc(&thread_count); + } + } + remove_wait_queue(&async_new, &wq); + + return 0; +} + +static int async_manager_thread(void *unused) +{ + DECLARE_WAITQUEUE(wq, current); + add_wait_queue(&async_new, &wq); + + while (!kthread_should_stop()) { + int tc, ec; + + set_current_state(TASK_INTERRUPTIBLE); + + tc = atomic_read(&thread_count); + rmb(); + ec = atomic_read(&entry_count); + + while (tc < ec && tc < MAX_THREADS) { + kthread_run(async_thread, NULL, "async/%i", tc); + atomic_inc(&thread_count); + tc++; + } + + schedule(); + } + remove_wait_queue(&async_new, &wq); + + return 0; +} + +static int __init async_init(void) +{ + kthread_run(async_manager_thread, NULL, "async/mgr"); + return 0; +} + +core_initcall(async_init); diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index cc0f7321b8ce..1de9700f416e 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/interrupt.h> #include <linux/delay.h> +#include <linux/async.h> #include "internals.h" @@ -34,6 +35,10 @@ unsigned long probe_irq_on(void) unsigned int status; int i; + /* + * quiesce the kernel, or at least the asynchronous portion + */ + async_synchronize_full(); mutex_lock(&probing_active); /* * something may have generated an irq long ago and we want to diff --git a/kernel/module.c b/kernel/module.c index 496dcb57b608..c9332c90d5a0 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -50,6 +50,7 @@ #include <asm/sections.h> #include <linux/tracepoint.h> #include <linux/ftrace.h> +#include <linux/async.h> #if 0 #define DEBUGP printk @@ -816,6 +817,7 @@ sys_delete_module(const char __user *name_user, unsigned int flags) mod->exit(); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); + async_synchronize_full(); mutex_lock(&module_mutex); /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); |