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Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

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* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Block: use round_jiffies_up()
  Add round_jiffies_up and related routines
  block: fix __blkdev_get() for removable devices
  generic-ipi: fix the smp_mb() placement
  blk: move blk_delete_timer call in end_that_request_last
  block: add timer on blkdev_dequeue_request() not elv_next_request()
  bio: define __BIOVEC_PHYS_MERGEABLE
  block: remove unused ll_new_mergeable()
This commit is contained in:
Linus Torvalds 2008-11-06 15:53:47 -08:00
commit e252f4db18
9 changed files with 153 additions and 105 deletions
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4
block/blk-core.c
View File

@ -1770,8 +1770,6 @@ static void end_that_request_last(struct request *req, int error)
{
struct gendisk *disk = req->rq_disk;
blk_delete_timer(req);
if (blk_rq_tagged(req))
blk_queue_end_tag(req->q, req);
@ -1781,6 +1779,8 @@ static void end_that_request_last(struct request *req, int error)
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
blk_delete_timer(req);
/*
* Account IO completion. bar_rq isn't accounted as a normal
* IO on queueing nor completion. Accounting the containing

21
block/blk-merge.c
View File

@ -222,27 +222,6 @@ new_segment:
}
EXPORT_SYMBOL(blk_rq_map_sg);
static inline int ll_new_mergeable(struct request_queue *q,
struct request *req,
struct bio *bio)
{
int nr_phys_segs = bio_phys_segments(q, bio);
if (req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
req->cmd_flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
return 0;
}
/*
* A hw segment is just getting larger, bump just the phys
* counter.
*/
req->nr_phys_segments += nr_phys_segs;
return 1;
}
static inline int ll_new_hw_segment(struct request_queue *q,
struct request *req,
struct bio *bio)

20
block/blk-timeout.c
View File

@ -75,14 +75,7 @@ void blk_delete_timer(struct request *req)
{
struct request_queue *q = req->q;
/*
* Nothing to detach
*/
if (!q->rq_timed_out_fn || !req->deadline)
return;
list_del_init(&req->timeout_list);
if (list_empty(&q->timeout_list))
del_timer(&q->timeout);
}
@ -142,7 +135,7 @@ void blk_rq_timed_out_timer(unsigned long data)
}
if (next_set && !list_empty(&q->timeout_list))
mod_timer(&q->timeout, round_jiffies(next));
mod_timer(&q->timeout, round_jiffies_up(next));
spin_unlock_irqrestore(q->queue_lock, flags);
}
@ -198,17 +191,10 @@ void blk_add_timer(struct request *req)
/*
* If the timer isn't already pending or this timeout is earlier
* than an existing one, modify the timer. Round to next nearest
* than an existing one, modify the timer. Round up to next nearest
* second.
*/
expiry = round_jiffies(req->deadline);
/*
* We use ->deadline == 0 to detect whether a timer was added or
* not, so just increase to next jiffy for that specific case
*/
if (unlikely(!req->deadline))
req->deadline = 1;
expiry = round_jiffies_up(req->deadline);
if (!timer_pending(&q->timeout) ||
time_before(expiry, q->timeout.expires))

12
block/elevator.c
View File

@ -773,12 +773,6 @@ struct request *elv_next_request(struct request_queue *q)
*/
rq->cmd_flags |= REQ_STARTED;
blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
/*
* We are now handing the request to the hardware,
* add the timeout handler
*/
blk_add_timer(rq);
}
if (!q->boundary_rq || q->boundary_rq == rq) {
@ -850,6 +844,12 @@ void elv_dequeue_request(struct request_queue *q, struct request *rq)
*/
if (blk_account_rq(rq))
q->in_flight++;
/*
* We are now handing the request to the hardware, add the
* timeout handler.
*/
blk_add_timer(rq);
}
EXPORT_SYMBOL(elv_dequeue_request);

23
fs/block_dev.c
View File

@ -986,7 +986,6 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
{
struct gendisk *disk;
struct hd_struct *part = NULL;
int ret;
int partno;
int perm = 0;
@ -1004,24 +1003,25 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
return ret;
}
ret = -ENXIO;
lock_kernel();
ret = -ENXIO;
disk = get_gendisk(bdev->bd_dev, &partno);
if (!disk)
goto out_unlock_kernel;
part = disk_get_part(disk, partno);
if (!part)
goto out_unlock_kernel;
mutex_lock_nested(&bdev->bd_mutex, for_part);
if (!bdev->bd_openers) {
bdev->bd_disk = disk;
bdev->bd_part = part;
bdev->bd_contains = bdev;
if (!partno) {
struct backing_dev_info *bdi;
ret = -ENXIO;
bdev->bd_part = disk_get_part(disk, partno);
if (!bdev->bd_part)
goto out_clear;
if (disk->fops->open) {
ret = disk->fops->open(bdev, mode);
if (ret)
@ -1049,18 +1049,17 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
bdev->bd_contains = whole;
bdev->bd_inode->i_data.backing_dev_info =
whole->bd_inode->i_data.backing_dev_info;
bdev->bd_part = disk_get_part(disk, partno);
if (!(disk->flags & GENHD_FL_UP) ||
!part || !part->nr_sects) {
!bdev->bd_part || !bdev->bd_part->nr_sects) {
ret = -ENXIO;
goto out_clear;
}
bd_set_size(bdev, (loff_t)part->nr_sects << 9);
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
}
} else {
disk_put_part(part);
put_disk(disk);
module_put(disk->fops->owner);
part = NULL;
disk = NULL;
if (bdev->bd_contains == bdev) {
if (bdev->bd_disk->fops->open) {
@ -1080,6 +1079,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
return 0;
out_clear:
disk_put_part(bdev->bd_part);
bdev->bd_disk = NULL;
bdev->bd_part = NULL;
bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
@ -1091,7 +1091,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
out_unlock_kernel:
unlock_kernel();
disk_put_part(part);
if (disk)
module_put(disk->fops->owner);
put_disk(disk);

6
include/linux/bio.h
View File

@ -236,12 +236,16 @@ static inline void *bio_data(struct bio *bio)
#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
/* Default implementation of BIOVEC_PHYS_MERGEABLE */
#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
/*
* allow arch override, for eg virtualized architectures (put in asm/io.h)
*/
#ifndef BIOVEC_PHYS_MERGEABLE
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
#endif
#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \

5
include/linux/timer.h
View File

@ -186,4 +186,9 @@ unsigned long __round_jiffies_relative(unsigned long j, int cpu);
unsigned long round_jiffies(unsigned long j);
unsigned long round_jiffies_relative(unsigned long j);
unsigned long __round_jiffies_up(unsigned long j, int cpu);
unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
unsigned long round_jiffies_up(unsigned long j);
unsigned long round_jiffies_up_relative(unsigned long j);
#endif

18
kernel/smp.c
View File

@ -51,10 +51,6 @@ static void csd_flag_wait(struct call_single_data *data)
{
/* Wait for response */
do {
/*
* We need to see the flags store in the IPI handler
*/
smp_mb();
if (!(data->flags & CSD_FLAG_WAIT))
break;
cpu_relax();
@ -76,6 +72,11 @@ static void generic_exec_single(int cpu, struct call_single_data *data)
list_add_tail(&data->list, &dst->list);
spin_unlock_irqrestore(&dst->lock, flags);
/*
* Make the list addition visible before sending the ipi.
*/
smp_mb();
if (ipi)
arch_send_call_function_single_ipi(cpu);
@ -157,7 +158,7 @@ void generic_smp_call_function_single_interrupt(void)
* Need to see other stores to list head for checking whether
* list is empty without holding q->lock
*/
smp_mb();
smp_read_barrier_depends();
while (!list_empty(&q->list)) {
unsigned int data_flags;
@ -191,7 +192,7 @@ void generic_smp_call_function_single_interrupt(void)
/*
* See comment on outer loop
*/
smp_mb();
smp_read_barrier_depends();
}
}
@ -370,6 +371,11 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
list_add_tail_rcu(&data->csd.list, &call_function_queue);
spin_unlock_irqrestore(&call_function_lock, flags);
/*
* Make the list addition visible before sending the ipi.
*/
smp_mb();
/* Send a message to all CPUs in the map */
arch_send_call_function_ipi(mask);

149
kernel/timer.c
View File

@ -112,6 +112,44 @@ timer_set_base(struct timer_list *timer, struct tvec_base *new_base)
tbase_get_deferrable(timer->base));
}
static unsigned long round_jiffies_common(unsigned long j, int cpu,
bool force_up)
{
int rem;
unsigned long original = j;
/*
* We don't want all cpus firing their timers at once hitting the
* same lock or cachelines, so we skew each extra cpu with an extra
* 3 jiffies. This 3 jiffies came originally from the mm/ code which
* already did this.
* The skew is done by adding 3*cpunr, then round, then subtract this
* extra offset again.
*/
j += cpu * 3;
rem = j % HZ;
/*
* If the target jiffie is just after a whole second (which can happen
* due to delays of the timer irq, long irq off times etc etc) then
* we should round down to the whole second, not up. Use 1/4th second
* as cutoff for this rounding as an extreme upper bound for this.
* But never round down if @force_up is set.
*/
if (rem < HZ/4 && !force_up) /* round down */
j = j - rem;
else /* round up */
j = j - rem + HZ;
/* now that we have rounded, subtract the extra skew again */
j -= cpu * 3;
if (j <= jiffies) /* rounding ate our timeout entirely; */
return original;
return j;
}
/**
* __round_jiffies - function to round jiffies to a full second
* @j: the time in (absolute) jiffies that should be rounded
@ -134,38 +172,7 @@ timer_set_base(struct timer_list *timer, struct tvec_base *new_base)
*/
unsigned long __round_jiffies(unsigned long j, int cpu)
{
int rem;
unsigned long original = j;
/*
* We don't want all cpus firing their timers at once hitting the
* same lock or cachelines, so we skew each extra cpu with an extra
* 3 jiffies. This 3 jiffies came originally from the mm/ code which
* already did this.
* The skew is done by adding 3*cpunr, then round, then subtract this
* extra offset again.
*/
j += cpu * 3;
rem = j % HZ;
/*
* If the target jiffie is just after a whole second (which can happen
* due to delays of the timer irq, long irq off times etc etc) then
* we should round down to the whole second, not up. Use 1/4th second
* as cutoff for this rounding as an extreme upper bound for this.
*/
if (rem < HZ/4) /* round down */
j = j - rem;
else /* round up */
j = j - rem + HZ;
/* now that we have rounded, subtract the extra skew again */
j -= cpu * 3;
if (j <= jiffies) /* rounding ate our timeout entirely; */
return original;
return j;
return round_jiffies_common(j, cpu, false);
}
EXPORT_SYMBOL_GPL(__round_jiffies);
@ -191,13 +198,10 @@ EXPORT_SYMBOL_GPL(__round_jiffies);
*/
unsigned long __round_jiffies_relative(unsigned long j, int cpu)
{
/*
* In theory the following code can skip a jiffy in case jiffies
* increments right between the addition and the later subtraction.
* However since the entire point of this function is to use approximate
* timeouts, it's entirely ok to not handle that.
*/
return __round_jiffies(j + jiffies, cpu) - jiffies;
unsigned long j0 = jiffies;
/* Use j0 because jiffies might change while we run */
return round_jiffies_common(j + j0, cpu, false) - j0;
}
EXPORT_SYMBOL_GPL(__round_jiffies_relative);
@ -218,7 +222,7 @@ EXPORT_SYMBOL_GPL(__round_jiffies_relative);
*/
unsigned long round_jiffies(unsigned long j)
{
return __round_jiffies(j, raw_smp_processor_id());
return round_jiffies_common(j, raw_smp_processor_id(), false);
}
EXPORT_SYMBOL_GPL(round_jiffies);
@ -243,6 +247,71 @@ unsigned long round_jiffies_relative(unsigned long j)
}
EXPORT_SYMBOL_GPL(round_jiffies_relative);
/**
* __round_jiffies_up - function to round jiffies up to a full second
* @j: the time in (absolute) jiffies that should be rounded
* @cpu: the processor number on which the timeout will happen
*
* This is the same as __round_jiffies() except that it will never
* round down. This is useful for timeouts for which the exact time
* of firing does not matter too much, as long as they don't fire too
* early.
*/
unsigned long __round_jiffies_up(unsigned long j, int cpu)
{
return round_jiffies_common(j, cpu, true);
}
EXPORT_SYMBOL_GPL(__round_jiffies_up);
/**
* __round_jiffies_up_relative - function to round jiffies up to a full second
* @j: the time in (relative) jiffies that should be rounded
* @cpu: the processor number on which the timeout will happen
*
* This is the same as __round_jiffies_relative() except that it will never
* round down. This is useful for timeouts for which the exact time
* of firing does not matter too much, as long as they don't fire too
* early.
*/
unsigned long __round_jiffies_up_relative(unsigned long j, int cpu)
{
unsigned long j0 = jiffies;
/* Use j0 because jiffies might change while we run */
return round_jiffies_common(j + j0, cpu, true) - j0;
}
EXPORT_SYMBOL_GPL(__round_jiffies_up_relative);
/**
* round_jiffies_up - function to round jiffies up to a full second
* @j: the time in (absolute) jiffies that should be rounded
*
* This is the same as round_jiffies() except that it will never
* round down. This is useful for timeouts for which the exact time
* of firing does not matter too much, as long as they don't fire too
* early.
*/
unsigned long round_jiffies_up(unsigned long j)
{
return round_jiffies_common(j, raw_smp_processor_id(), true);
}
EXPORT_SYMBOL_GPL(round_jiffies_up);
/**
* round_jiffies_up_relative - function to round jiffies up to a full second
* @j: the time in (relative) jiffies that should be rounded
*
* This is the same as round_jiffies_relative() except that it will never
* round down. This is useful for timeouts for which the exact time
* of firing does not matter too much, as long as they don't fire too
* early.
*/
unsigned long round_jiffies_up_relative(unsigned long j)
{
return __round_jiffies_up_relative(j, raw_smp_processor_id());
}
EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
static inline void set_running_timer(struct tvec_base *base,
struct timer_list *timer)