mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 10:40:15 +02:00 
			
		
		
		
	fscache: convert object to use workqueue instead of slow-work
Make fscache object state transition callbacks use workqueue instead of slow-work. New dedicated unbound CPU workqueue fscache_object_wq is created. get/put callbacks are renamed and modified to take @object and called directly from the enqueue wrapper and the work function. While at it, make all open coded instances of get/put to use fscache_get/put_object(). * Unbound workqueue is used. * work_busy() output is printed instead of slow-work flags in object debugging outputs. They mean basically the same thing bit-for-bit. * sysctl fscache.object_max_active added to control concurrency. The default value is nr_cpus clamped between 4 and WQ_UNBOUND_MAX_ACTIVE. * slow_work_sleep_till_thread_needed() is replaced with fscache private implementation fscache_object_sleep_till_congested() which waits on fscache_object_wq congestion. * debugfs support is dropped for now. Tracing API based debug facility is planned to be added. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David Howells <dhowells@redhat.com>
This commit is contained in:
		
							parent
							
								
									e120153ddf
								
							
						
					
					
						commit
						8b8edefa2f
					
				
					 7 changed files with 158 additions and 74 deletions
				
			
		| 
						 | 
				
			
			@ -343,8 +343,8 @@ This will look something like:
 | 
			
		|||
	[root@andromeda ~]# head /proc/fs/fscache/objects
 | 
			
		||||
	OBJECT   PARENT   STAT CHLDN OPS OOP IPR EX READS EM EV F S | NETFS_COOKIE_DEF TY FL NETFS_DATA       OBJECT_KEY, AUX_DATA
 | 
			
		||||
	======== ======== ==== ===== === === === == ===== == == = = | ================ == == ================ ================
 | 
			
		||||
	   17e4b        2 ACTV     0   0   0   0  0     0 7b  4 0 8 | NFS.fh           DT  0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a
 | 
			
		||||
	   1693a        2 ACTV     0   0   0   0  0     0 7b  4 0 8 | NFS.fh           DT  0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a
 | 
			
		||||
	   17e4b        2 ACTV     0   0   0   0  0     0 7b  4 0 0 | NFS.fh           DT  0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a
 | 
			
		||||
	   1693a        2 ACTV     0   0   0   0  0     0 7b  4 0 0 | NFS.fh           DT  0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a
 | 
			
		||||
 | 
			
		||||
where the first set of columns before the '|' describe the object:
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -362,7 +362,7 @@ where the first set of columns before the '|' describe the object:
 | 
			
		|||
	EM	Object's event mask
 | 
			
		||||
	EV	Events raised on this object
 | 
			
		||||
	F	Object flags
 | 
			
		||||
	S	Object slow-work work item flags
 | 
			
		||||
	S	Object work item busy state mask (1:pending 2:running)
 | 
			
		||||
 | 
			
		||||
and the second set of columns describe the object's cookie, if present:
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -395,8 +395,8 @@ and the following paired letters:
 | 
			
		|||
	w	Show objects that don't have pending writes
 | 
			
		||||
	R	Show objects that have outstanding reads
 | 
			
		||||
	r	Show objects that don't have outstanding reads
 | 
			
		||||
	S	Show objects that have slow work queued
 | 
			
		||||
	s	Show objects that don't have slow work queued
 | 
			
		||||
	S	Show objects that have work queued
 | 
			
		||||
	s	Show objects that don't have work queued
 | 
			
		||||
 | 
			
		||||
If neither side of a letter pair is given, then both are implied.  For example:
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -37,9 +37,9 @@ void __cachefiles_printk_object(struct cachefiles_object *object,
 | 
			
		|||
 | 
			
		||||
	printk(KERN_ERR "%sobject: OBJ%x\n",
 | 
			
		||||
	       prefix, object->fscache.debug_id);
 | 
			
		||||
	printk(KERN_ERR "%sobjstate=%s fl=%lx swfl=%lx ev=%lx[%lx]\n",
 | 
			
		||||
	printk(KERN_ERR "%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n",
 | 
			
		||||
	       prefix, fscache_object_states[object->fscache.state],
 | 
			
		||||
	       object->fscache.flags, object->fscache.work.flags,
 | 
			
		||||
	       object->fscache.flags, work_busy(&object->fscache.work),
 | 
			
		||||
	       object->fscache.events,
 | 
			
		||||
	       object->fscache.event_mask & FSCACHE_OBJECT_EVENTS_MASK);
 | 
			
		||||
	printk(KERN_ERR "%sops=%u inp=%u exc=%u\n",
 | 
			
		||||
| 
						 | 
				
			
			@ -212,7 +212,7 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
 | 
			
		|||
 | 
			
		||||
		/* if the object we're waiting for is queued for processing,
 | 
			
		||||
		 * then just put ourselves on the queue behind it */
 | 
			
		||||
		if (slow_work_is_queued(&xobject->fscache.work)) {
 | 
			
		||||
		if (work_pending(&xobject->fscache.work)) {
 | 
			
		||||
			_debug("queue OBJ%x behind OBJ%x immediately",
 | 
			
		||||
			       object->fscache.debug_id,
 | 
			
		||||
			       xobject->fscache.debug_id);
 | 
			
		||||
| 
						 | 
				
			
			@ -220,8 +220,7 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
 | 
			
		|||
		}
 | 
			
		||||
 | 
			
		||||
		/* otherwise we sleep until either the object we're waiting for
 | 
			
		||||
		 * is done, or the slow-work facility wants the thread back to
 | 
			
		||||
		 * do other work */
 | 
			
		||||
		 * is done, or the fscache_object is congested */
 | 
			
		||||
		wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE);
 | 
			
		||||
		init_wait(&wait);
 | 
			
		||||
		requeue = false;
 | 
			
		||||
| 
						 | 
				
			
			@ -229,8 +228,8 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
 | 
			
		|||
			prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
 | 
			
		||||
			if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags))
 | 
			
		||||
				break;
 | 
			
		||||
			requeue = slow_work_sleep_till_thread_needed(
 | 
			
		||||
				&object->fscache.work, &timeout);
 | 
			
		||||
 | 
			
		||||
			requeue = fscache_object_sleep_till_congested(&timeout);
 | 
			
		||||
		} while (timeout > 0 && !requeue);
 | 
			
		||||
		finish_wait(wq, &wait);
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -82,6 +82,13 @@ extern unsigned fscache_defer_lookup;
 | 
			
		|||
extern unsigned fscache_defer_create;
 | 
			
		||||
extern unsigned fscache_debug;
 | 
			
		||||
extern struct kobject *fscache_root;
 | 
			
		||||
extern struct workqueue_struct *fscache_object_wq;
 | 
			
		||||
DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
 | 
			
		||||
 | 
			
		||||
static inline bool fscache_object_congested(void)
 | 
			
		||||
{
 | 
			
		||||
	return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
extern int fscache_wait_bit(void *);
 | 
			
		||||
extern int fscache_wait_bit_interruptible(void *);
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -15,6 +15,7 @@
 | 
			
		|||
#include <linux/sched.h>
 | 
			
		||||
#include <linux/completion.h>
 | 
			
		||||
#include <linux/slab.h>
 | 
			
		||||
#include <linux/seq_file.h>
 | 
			
		||||
#include "internal.h"
 | 
			
		||||
 | 
			
		||||
MODULE_DESCRIPTION("FS Cache Manager");
 | 
			
		||||
| 
						 | 
				
			
			@ -40,22 +41,89 @@ MODULE_PARM_DESC(fscache_debug,
 | 
			
		|||
		 "FS-Cache debugging mask");
 | 
			
		||||
 | 
			
		||||
struct kobject *fscache_root;
 | 
			
		||||
struct workqueue_struct *fscache_object_wq;
 | 
			
		||||
 | 
			
		||||
DEFINE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
 | 
			
		||||
 | 
			
		||||
/* these values serve as lower bounds, will be adjusted in fscache_init() */
 | 
			
		||||
static unsigned fscache_object_max_active = 4;
 | 
			
		||||
 | 
			
		||||
#ifdef CONFIG_SYSCTL
 | 
			
		||||
static struct ctl_table_header *fscache_sysctl_header;
 | 
			
		||||
 | 
			
		||||
static int fscache_max_active_sysctl(struct ctl_table *table, int write,
 | 
			
		||||
				     void __user *buffer,
 | 
			
		||||
				     size_t *lenp, loff_t *ppos)
 | 
			
		||||
{
 | 
			
		||||
	struct workqueue_struct **wqp = table->extra1;
 | 
			
		||||
	unsigned int *datap = table->data;
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	ret = proc_dointvec(table, write, buffer, lenp, ppos);
 | 
			
		||||
	if (ret == 0)
 | 
			
		||||
		workqueue_set_max_active(*wqp, *datap);
 | 
			
		||||
	return ret;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
ctl_table fscache_sysctls[] = {
 | 
			
		||||
	{
 | 
			
		||||
		.procname	= "object_max_active",
 | 
			
		||||
		.data		= &fscache_object_max_active,
 | 
			
		||||
		.maxlen		= sizeof(unsigned),
 | 
			
		||||
		.mode		= 0644,
 | 
			
		||||
		.proc_handler	= fscache_max_active_sysctl,
 | 
			
		||||
		.extra1		= &fscache_object_wq,
 | 
			
		||||
	},
 | 
			
		||||
	{}
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
ctl_table fscache_sysctls_root[] = {
 | 
			
		||||
	{
 | 
			
		||||
		.procname	= "fscache",
 | 
			
		||||
		.mode		= 0555,
 | 
			
		||||
		.child		= fscache_sysctls,
 | 
			
		||||
	},
 | 
			
		||||
	{}
 | 
			
		||||
};
 | 
			
		||||
#endif
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * initialise the fs caching module
 | 
			
		||||
 */
 | 
			
		||||
static int __init fscache_init(void)
 | 
			
		||||
{
 | 
			
		||||
	unsigned int nr_cpus = num_possible_cpus();
 | 
			
		||||
	unsigned int cpu;
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	ret = slow_work_register_user(THIS_MODULE);
 | 
			
		||||
	if (ret < 0)
 | 
			
		||||
		goto error_slow_work;
 | 
			
		||||
 | 
			
		||||
	fscache_object_max_active =
 | 
			
		||||
		clamp_val(nr_cpus,
 | 
			
		||||
			  fscache_object_max_active, WQ_UNBOUND_MAX_ACTIVE);
 | 
			
		||||
 | 
			
		||||
	ret = -ENOMEM;
 | 
			
		||||
	fscache_object_wq = alloc_workqueue("fscache_object", WQ_UNBOUND,
 | 
			
		||||
					    fscache_object_max_active);
 | 
			
		||||
	if (!fscache_object_wq)
 | 
			
		||||
		goto error_object_wq;
 | 
			
		||||
 | 
			
		||||
	for_each_possible_cpu(cpu)
 | 
			
		||||
		init_waitqueue_head(&per_cpu(fscache_object_cong_wait, cpu));
 | 
			
		||||
 | 
			
		||||
	ret = fscache_proc_init();
 | 
			
		||||
	if (ret < 0)
 | 
			
		||||
		goto error_proc;
 | 
			
		||||
 | 
			
		||||
#ifdef CONFIG_SYSCTL
 | 
			
		||||
	ret = -ENOMEM;
 | 
			
		||||
	fscache_sysctl_header = register_sysctl_table(fscache_sysctls_root);
 | 
			
		||||
	if (!fscache_sysctl_header)
 | 
			
		||||
		goto error_sysctl;
 | 
			
		||||
#endif
 | 
			
		||||
 | 
			
		||||
	fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",
 | 
			
		||||
					       sizeof(struct fscache_cookie),
 | 
			
		||||
					       0,
 | 
			
		||||
| 
						 | 
				
			
			@ -78,8 +146,14 @@ static int __init fscache_init(void)
 | 
			
		|||
error_kobj:
 | 
			
		||||
	kmem_cache_destroy(fscache_cookie_jar);
 | 
			
		||||
error_cookie_jar:
 | 
			
		||||
#ifdef CONFIG_SYSCTL
 | 
			
		||||
	unregister_sysctl_table(fscache_sysctl_header);
 | 
			
		||||
error_sysctl:
 | 
			
		||||
#endif
 | 
			
		||||
	fscache_proc_cleanup();
 | 
			
		||||
error_proc:
 | 
			
		||||
	destroy_workqueue(fscache_object_wq);
 | 
			
		||||
error_object_wq:
 | 
			
		||||
	slow_work_unregister_user(THIS_MODULE);
 | 
			
		||||
error_slow_work:
 | 
			
		||||
	return ret;
 | 
			
		||||
| 
						 | 
				
			
			@ -96,7 +170,9 @@ static void __exit fscache_exit(void)
 | 
			
		|||
 | 
			
		||||
	kobject_put(fscache_root);
 | 
			
		||||
	kmem_cache_destroy(fscache_cookie_jar);
 | 
			
		||||
	unregister_sysctl_table(fscache_sysctl_header);
 | 
			
		||||
	fscache_proc_cleanup();
 | 
			
		||||
	destroy_workqueue(fscache_object_wq);
 | 
			
		||||
	slow_work_unregister_user(THIS_MODULE);
 | 
			
		||||
	printk(KERN_NOTICE "FS-Cache: Unloaded\n");
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -34,8 +34,8 @@ struct fscache_objlist_data {
 | 
			
		|||
#define FSCACHE_OBJLIST_CONFIG_NOREADS	0x00000200	/* show objects without active reads */
 | 
			
		||||
#define FSCACHE_OBJLIST_CONFIG_EVENTS	0x00000400	/* show objects with events */
 | 
			
		||||
#define FSCACHE_OBJLIST_CONFIG_NOEVENTS	0x00000800	/* show objects without no events */
 | 
			
		||||
#define FSCACHE_OBJLIST_CONFIG_WORK	0x00001000	/* show objects with slow work */
 | 
			
		||||
#define FSCACHE_OBJLIST_CONFIG_NOWORK	0x00002000	/* show objects without slow work */
 | 
			
		||||
#define FSCACHE_OBJLIST_CONFIG_WORK	0x00001000	/* show objects with work */
 | 
			
		||||
#define FSCACHE_OBJLIST_CONFIG_NOWORK	0x00002000	/* show objects without work */
 | 
			
		||||
 | 
			
		||||
	u8		buf[512];	/* key and aux data buffer */
 | 
			
		||||
};
 | 
			
		||||
| 
						 | 
				
			
			@ -231,12 +231,11 @@ static int fscache_objlist_show(struct seq_file *m, void *v)
 | 
			
		|||
		       READS, NOREADS);
 | 
			
		||||
		FILTER(obj->events & obj->event_mask,
 | 
			
		||||
		       EVENTS, NOEVENTS);
 | 
			
		||||
		FILTER(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW),
 | 
			
		||||
		       WORK, NOWORK);
 | 
			
		||||
		FILTER(work_busy(&obj->work), WORK, NOWORK);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	seq_printf(m,
 | 
			
		||||
		   "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx | ",
 | 
			
		||||
		   "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1x | ",
 | 
			
		||||
		   obj->debug_id,
 | 
			
		||||
		   obj->parent ? obj->parent->debug_id : -1,
 | 
			
		||||
		   fscache_object_states_short[obj->state],
 | 
			
		||||
| 
						 | 
				
			
			@ -249,7 +248,7 @@ static int fscache_objlist_show(struct seq_file *m, void *v)
 | 
			
		|||
		   obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK,
 | 
			
		||||
		   obj->events,
 | 
			
		||||
		   obj->flags,
 | 
			
		||||
		   obj->work.flags);
 | 
			
		||||
		   work_busy(&obj->work));
 | 
			
		||||
 | 
			
		||||
	no_cookie = true;
 | 
			
		||||
	keylen = auxlen = 0;
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -14,7 +14,6 @@
 | 
			
		|||
 | 
			
		||||
#define FSCACHE_DEBUG_LEVEL COOKIE
 | 
			
		||||
#include <linux/module.h>
 | 
			
		||||
#include <linux/seq_file.h>
 | 
			
		||||
#include "internal.h"
 | 
			
		||||
 | 
			
		||||
const char *fscache_object_states[FSCACHE_OBJECT__NSTATES] = {
 | 
			
		||||
| 
						 | 
				
			
			@ -50,12 +49,8 @@ const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5] = {
 | 
			
		|||
	[FSCACHE_OBJECT_DEAD]		= "DEAD",
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
static void fscache_object_slow_work_put_ref(struct slow_work *);
 | 
			
		||||
static int  fscache_object_slow_work_get_ref(struct slow_work *);
 | 
			
		||||
static void fscache_object_slow_work_execute(struct slow_work *);
 | 
			
		||||
#ifdef CONFIG_SLOW_WORK_DEBUG
 | 
			
		||||
static void fscache_object_slow_work_desc(struct slow_work *, struct seq_file *);
 | 
			
		||||
#endif
 | 
			
		||||
static int  fscache_get_object(struct fscache_object *);
 | 
			
		||||
static void fscache_put_object(struct fscache_object *);
 | 
			
		||||
static void fscache_initialise_object(struct fscache_object *);
 | 
			
		||||
static void fscache_lookup_object(struct fscache_object *);
 | 
			
		||||
static void fscache_object_available(struct fscache_object *);
 | 
			
		||||
| 
						 | 
				
			
			@ -64,17 +59,6 @@ static void fscache_withdraw_object(struct fscache_object *);
 | 
			
		|||
static void fscache_enqueue_dependents(struct fscache_object *);
 | 
			
		||||
static void fscache_dequeue_object(struct fscache_object *);
 | 
			
		||||
 | 
			
		||||
const struct slow_work_ops fscache_object_slow_work_ops = {
 | 
			
		||||
	.owner		= THIS_MODULE,
 | 
			
		||||
	.get_ref	= fscache_object_slow_work_get_ref,
 | 
			
		||||
	.put_ref	= fscache_object_slow_work_put_ref,
 | 
			
		||||
	.execute	= fscache_object_slow_work_execute,
 | 
			
		||||
#ifdef CONFIG_SLOW_WORK_DEBUG
 | 
			
		||||
	.desc		= fscache_object_slow_work_desc,
 | 
			
		||||
#endif
 | 
			
		||||
};
 | 
			
		||||
EXPORT_SYMBOL(fscache_object_slow_work_ops);
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * we need to notify the parent when an op completes that we had outstanding
 | 
			
		||||
 * upon it
 | 
			
		||||
| 
						 | 
				
			
			@ -345,7 +329,7 @@ static void fscache_object_state_machine(struct fscache_object *object)
 | 
			
		|||
/*
 | 
			
		||||
 * execute an object
 | 
			
		||||
 */
 | 
			
		||||
static void fscache_object_slow_work_execute(struct slow_work *work)
 | 
			
		||||
void fscache_object_work_func(struct work_struct *work)
 | 
			
		||||
{
 | 
			
		||||
	struct fscache_object *object =
 | 
			
		||||
		container_of(work, struct fscache_object, work);
 | 
			
		||||
| 
						 | 
				
			
			@ -359,23 +343,9 @@ static void fscache_object_slow_work_execute(struct slow_work *work)
 | 
			
		|||
	if (object->events & object->event_mask)
 | 
			
		||||
		fscache_enqueue_object(object);
 | 
			
		||||
	clear_bit(FSCACHE_OBJECT_EV_REQUEUE, &object->events);
 | 
			
		||||
	fscache_put_object(object);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * describe an object for slow-work debugging
 | 
			
		||||
 */
 | 
			
		||||
#ifdef CONFIG_SLOW_WORK_DEBUG
 | 
			
		||||
static void fscache_object_slow_work_desc(struct slow_work *work,
 | 
			
		||||
					  struct seq_file *m)
 | 
			
		||||
{
 | 
			
		||||
	struct fscache_object *object =
 | 
			
		||||
		container_of(work, struct fscache_object, work);
 | 
			
		||||
 | 
			
		||||
	seq_printf(m, "FSC: OBJ%x: %s",
 | 
			
		||||
		   object->debug_id,
 | 
			
		||||
		   fscache_object_states_short[object->state]);
 | 
			
		||||
}
 | 
			
		||||
#endif
 | 
			
		||||
EXPORT_SYMBOL(fscache_object_work_func);
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * initialise an object
 | 
			
		||||
| 
						 | 
				
			
			@ -393,7 +363,6 @@ static void fscache_initialise_object(struct fscache_object *object)
 | 
			
		|||
	_enter("");
 | 
			
		||||
	ASSERT(object->cookie != NULL);
 | 
			
		||||
	ASSERT(object->cookie->parent != NULL);
 | 
			
		||||
	ASSERT(list_empty(&object->work.link));
 | 
			
		||||
 | 
			
		||||
	if (object->events & ((1 << FSCACHE_OBJECT_EV_ERROR) |
 | 
			
		||||
			      (1 << FSCACHE_OBJECT_EV_RELEASE) |
 | 
			
		||||
| 
						 | 
				
			
			@ -671,10 +640,8 @@ static void fscache_drop_object(struct fscache_object *object)
 | 
			
		|||
		object->parent = NULL;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/* this just shifts the object release to the slow work processor */
 | 
			
		||||
	fscache_stat(&fscache_n_cop_put_object);
 | 
			
		||||
	object->cache->ops->put_object(object);
 | 
			
		||||
	fscache_stat_d(&fscache_n_cop_put_object);
 | 
			
		||||
	/* this just shifts the object release to the work processor */
 | 
			
		||||
	fscache_put_object(object);
 | 
			
		||||
 | 
			
		||||
	_leave("");
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			@ -758,12 +725,10 @@ void fscache_withdrawing_object(struct fscache_cache *cache,
 | 
			
		|||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * allow the slow work item processor to get a ref on an object
 | 
			
		||||
 * get a ref on an object
 | 
			
		||||
 */
 | 
			
		||||
static int fscache_object_slow_work_get_ref(struct slow_work *work)
 | 
			
		||||
static int fscache_get_object(struct fscache_object *object)
 | 
			
		||||
{
 | 
			
		||||
	struct fscache_object *object =
 | 
			
		||||
		container_of(work, struct fscache_object, work);
 | 
			
		||||
	int ret;
 | 
			
		||||
 | 
			
		||||
	fscache_stat(&fscache_n_cop_grab_object);
 | 
			
		||||
| 
						 | 
				
			
			@ -773,13 +738,10 @@ static int fscache_object_slow_work_get_ref(struct slow_work *work)
 | 
			
		|||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * allow the slow work item processor to discard a ref on a work item
 | 
			
		||||
 * discard a ref on a work item
 | 
			
		||||
 */
 | 
			
		||||
static void fscache_object_slow_work_put_ref(struct slow_work *work)
 | 
			
		||||
static void fscache_put_object(struct fscache_object *object)
 | 
			
		||||
{
 | 
			
		||||
	struct fscache_object *object =
 | 
			
		||||
		container_of(work, struct fscache_object, work);
 | 
			
		||||
 | 
			
		||||
	fscache_stat(&fscache_n_cop_put_object);
 | 
			
		||||
	object->cache->ops->put_object(object);
 | 
			
		||||
	fscache_stat_d(&fscache_n_cop_put_object);
 | 
			
		||||
| 
						 | 
				
			
			@ -792,9 +754,49 @@ void fscache_enqueue_object(struct fscache_object *object)
 | 
			
		|||
{
 | 
			
		||||
	_enter("{OBJ%x}", object->debug_id);
 | 
			
		||||
 | 
			
		||||
	slow_work_enqueue(&object->work);
 | 
			
		||||
	if (fscache_get_object(object) >= 0) {
 | 
			
		||||
		wait_queue_head_t *cong_wq =
 | 
			
		||||
			&get_cpu_var(fscache_object_cong_wait);
 | 
			
		||||
 | 
			
		||||
		if (queue_work(fscache_object_wq, &object->work)) {
 | 
			
		||||
			if (fscache_object_congested())
 | 
			
		||||
				wake_up(cong_wq);
 | 
			
		||||
		} else
 | 
			
		||||
			fscache_put_object(object);
 | 
			
		||||
 | 
			
		||||
		put_cpu_var(fscache_object_cong_wait);
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * fscache_object_sleep_till_congested - Sleep until object wq is congested
 | 
			
		||||
 * @timoutp: Scheduler sleep timeout
 | 
			
		||||
 *
 | 
			
		||||
 * Allow an object handler to sleep until the object workqueue is congested.
 | 
			
		||||
 *
 | 
			
		||||
 * The caller must set up a wake up event before calling this and must have set
 | 
			
		||||
 * the appropriate sleep mode (such as TASK_UNINTERRUPTIBLE) and tested its own
 | 
			
		||||
 * condition before calling this function as no test is made here.
 | 
			
		||||
 *
 | 
			
		||||
 * %true is returned if the object wq is congested, %false otherwise.
 | 
			
		||||
 */
 | 
			
		||||
bool fscache_object_sleep_till_congested(signed long *timeoutp)
 | 
			
		||||
{
 | 
			
		||||
	wait_queue_head_t *cong_wq = &__get_cpu_var(fscache_object_cong_wait);
 | 
			
		||||
	DEFINE_WAIT(wait);
 | 
			
		||||
 | 
			
		||||
	if (fscache_object_congested())
 | 
			
		||||
		return true;
 | 
			
		||||
 | 
			
		||||
	add_wait_queue_exclusive(cong_wq, &wait);
 | 
			
		||||
	if (!fscache_object_congested())
 | 
			
		||||
		*timeoutp = schedule_timeout(*timeoutp);
 | 
			
		||||
	finish_wait(cong_wq, &wait);
 | 
			
		||||
 | 
			
		||||
	return fscache_object_congested();
 | 
			
		||||
}
 | 
			
		||||
EXPORT_SYMBOL_GPL(fscache_object_sleep_till_congested);
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * enqueue the dependents of an object for metadata-type processing
 | 
			
		||||
 * - the caller must hold the object's lock
 | 
			
		||||
| 
						 | 
				
			
			@ -819,9 +821,7 @@ static void fscache_enqueue_dependents(struct fscache_object *object)
 | 
			
		|||
 | 
			
		||||
		/* sort onto appropriate lists */
 | 
			
		||||
		fscache_enqueue_object(dep);
 | 
			
		||||
		fscache_stat(&fscache_n_cop_put_object);
 | 
			
		||||
		dep->cache->ops->put_object(dep);
 | 
			
		||||
		fscache_stat_d(&fscache_n_cop_put_object);
 | 
			
		||||
		fscache_put_object(dep);
 | 
			
		||||
 | 
			
		||||
		if (!list_empty(&object->dependents))
 | 
			
		||||
			cond_resched_lock(&object->lock);
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -21,6 +21,7 @@
 | 
			
		|||
#include <linux/fscache.h>
 | 
			
		||||
#include <linux/sched.h>
 | 
			
		||||
#include <linux/slow-work.h>
 | 
			
		||||
#include <linux/workqueue.h>
 | 
			
		||||
 | 
			
		||||
#define NR_MAXCACHES BITS_PER_LONG
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -389,7 +390,7 @@ struct fscache_object {
 | 
			
		|||
	struct fscache_cache	*cache;		/* cache that supplied this object */
 | 
			
		||||
	struct fscache_cookie	*cookie;	/* netfs's file/index object */
 | 
			
		||||
	struct fscache_object	*parent;	/* parent object */
 | 
			
		||||
	struct slow_work	work;		/* attention scheduling record */
 | 
			
		||||
	struct work_struct	work;		/* attention scheduling record */
 | 
			
		||||
	struct list_head	dependents;	/* FIFO of dependent objects */
 | 
			
		||||
	struct list_head	dep_link;	/* link in parent's dependents list */
 | 
			
		||||
	struct list_head	pending_ops;	/* unstarted operations on this object */
 | 
			
		||||
| 
						 | 
				
			
			@ -411,7 +412,7 @@ extern const char *fscache_object_states[];
 | 
			
		|||
	(test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) &&	\
 | 
			
		||||
	 (obj)->state >= FSCACHE_OBJECT_DYING)
 | 
			
		||||
 | 
			
		||||
extern const struct slow_work_ops fscache_object_slow_work_ops;
 | 
			
		||||
extern void fscache_object_work_func(struct work_struct *work);
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * fscache_object_init - Initialise a cache object description
 | 
			
		||||
| 
						 | 
				
			
			@ -433,7 +434,7 @@ void fscache_object_init(struct fscache_object *object,
 | 
			
		|||
	spin_lock_init(&object->lock);
 | 
			
		||||
	INIT_LIST_HEAD(&object->cache_link);
 | 
			
		||||
	INIT_HLIST_NODE(&object->cookie_link);
 | 
			
		||||
	vslow_work_init(&object->work, &fscache_object_slow_work_ops);
 | 
			
		||||
	INIT_WORK(&object->work, fscache_object_work_func);
 | 
			
		||||
	INIT_LIST_HEAD(&object->dependents);
 | 
			
		||||
	INIT_LIST_HEAD(&object->dep_link);
 | 
			
		||||
	INIT_LIST_HEAD(&object->pending_ops);
 | 
			
		||||
| 
						 | 
				
			
			@ -534,6 +535,8 @@ extern void fscache_io_error(struct fscache_cache *cache);
 | 
			
		|||
extern void fscache_mark_pages_cached(struct fscache_retrieval *op,
 | 
			
		||||
				      struct pagevec *pagevec);
 | 
			
		||||
 | 
			
		||||
extern bool fscache_object_sleep_till_congested(signed long *timeoutp);
 | 
			
		||||
 | 
			
		||||
extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
 | 
			
		||||
					       const void *data,
 | 
			
		||||
					       uint16_t datalen);
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in a new issue