Skip to content

Commit

Permalink
[PATCH] kill __init_timer_base in favor of boot_tvec_bases
Browse files Browse the repository at this point in the history 
Commit a4a6198:
	[PATCH] tvec_bases too large for per-cpu data

introduced "struct tvec_t_base_s boot_tvec_bases" which is visible at
compile time.  This means we can kill __init_timer_base and move
timer_base_s's content into tvec_t_base_s.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
  • Loading branch information
Oleg Nesterov authored and Linus Torvalds committed Mar 31, 2006
1 parent 5ce2964 commit 3691c51
Show file tree
Hide file tree
Showing 2 changed files with 39 additions and 53 deletions.
8 changes: 4 additions & 4 deletions include/linux/timer.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
#include <linux/spinlock.h>
#include <linux/stddef.h>

struct timer_base_s;
struct tvec_t_base_s;

struct timer_list {
struct list_head entry;
Expand All @@ -15,16 +15,16 @@ struct timer_list {
void (*function)(unsigned long);
unsigned long data;

struct timer_base_s *base;
struct tvec_t_base_s *base;
};

extern struct timer_base_s __init_timer_base;
extern struct tvec_t_base_s boot_tvec_bases;

#define TIMER_INITIALIZER(_function, _expires, _data) { \
.function = (_function), \
.expires = (_expires), \
.data = (_data), \
.base = &__init_timer_base, \
.base = &boot_tvec_bases, \
}

#define DEFINE_TIMER(_name, _function, _expires, _data) \
Expand Down
84 changes: 35 additions & 49 deletions kernel/timer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,19 +54,13 @@ EXPORT_SYMBOL(jiffies_64);
/*
* per-CPU timer vector definitions:
*/

#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
#define TVN_SIZE (1 << TVN_BITS)
#define TVR_SIZE (1 << TVR_BITS)
#define TVN_MASK (TVN_SIZE - 1)
#define TVR_MASK (TVR_SIZE - 1)

struct timer_base_s {
spinlock_t lock;
struct timer_list *running_timer;
};

typedef struct tvec_s {
struct list_head vec[TVN_SIZE];
} tvec_t;
Expand All @@ -76,7 +70,8 @@ typedef struct tvec_root_s {
} tvec_root_t;

struct tvec_t_base_s {
struct timer_base_s t_base;
spinlock_t lock;
struct timer_list *running_timer;
unsigned long timer_jiffies;
tvec_root_t tv1;
tvec_t tv2;
Expand All @@ -87,13 +82,14 @@ struct tvec_t_base_s {

typedef struct tvec_t_base_s tvec_base_t;
static DEFINE_PER_CPU(tvec_base_t *, tvec_bases);
static tvec_base_t boot_tvec_bases;
tvec_base_t boot_tvec_bases;
EXPORT_SYMBOL(boot_tvec_bases);

static inline void set_running_timer(tvec_base_t *base,
struct timer_list *timer)
{
#ifdef CONFIG_SMP
base->t_base.running_timer = timer;
base->running_timer = timer;
#endif
}

Expand Down Expand Up @@ -139,15 +135,6 @@ static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
list_add_tail(&timer->entry, vec);
}

typedef struct timer_base_s timer_base_t;
/*
* Used by TIMER_INITIALIZER, we can't use per_cpu(tvec_bases)
* at compile time, and we need timer->base to lock the timer.
*/
timer_base_t __init_timer_base
____cacheline_aligned_in_smp = { .lock = SPIN_LOCK_UNLOCKED };
EXPORT_SYMBOL(__init_timer_base);

/***
* init_timer - initialize a timer.
* @timer: the timer to be initialized
Expand All @@ -158,7 +145,7 @@ EXPORT_SYMBOL(__init_timer_base);
void fastcall init_timer(struct timer_list *timer)
{
timer->entry.next = NULL;
timer->base = &per_cpu(tvec_bases, raw_smp_processor_id())->t_base;
timer->base = per_cpu(tvec_bases, raw_smp_processor_id());
}
EXPORT_SYMBOL(init_timer);

Expand All @@ -174,7 +161,7 @@ static inline void detach_timer(struct timer_list *timer,
}

/*
* We are using hashed locking: holding per_cpu(tvec_bases).t_base.lock
* We are using hashed locking: holding per_cpu(tvec_bases).lock
* means that all timers which are tied to this base via timer->base are
* locked, and the base itself is locked too.
*
Expand All @@ -185,10 +172,10 @@ static inline void detach_timer(struct timer_list *timer,
* possible to set timer->base = NULL and drop the lock: the timer remains
* locked.
*/
static timer_base_t *lock_timer_base(struct timer_list *timer,
static tvec_base_t *lock_timer_base(struct timer_list *timer,
unsigned long *flags)
{
timer_base_t *base;
tvec_base_t *base;

for (;;) {
base = timer->base;
Expand All @@ -205,8 +192,7 @@ static timer_base_t *lock_timer_base(struct timer_list *timer,

int __mod_timer(struct timer_list *timer, unsigned long expires)
{
timer_base_t *base;
tvec_base_t *new_base;
tvec_base_t *base, *new_base;
unsigned long flags;
int ret = 0;

Expand All @@ -221,7 +207,7 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)

new_base = __get_cpu_var(tvec_bases);

if (base != &new_base->t_base) {
if (base != new_base) {
/*
* We are trying to schedule the timer on the local CPU.
* However we can't change timer's base while it is running,
Expand All @@ -231,19 +217,19 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
*/
if (unlikely(base->running_timer == timer)) {
/* The timer remains on a former base */
new_base = container_of(base, tvec_base_t, t_base);
new_base = base;
} else {
/* See the comment in lock_timer_base() */
timer->base = NULL;
spin_unlock(&base->lock);
spin_lock(&new_base->t_base.lock);
timer->base = &new_base->t_base;
spin_lock(&new_base->lock);
timer->base = new_base;
}
}

timer->expires = expires;
internal_add_timer(new_base, timer);
spin_unlock_irqrestore(&new_base->t_base.lock, flags);
spin_unlock_irqrestore(&new_base->lock, flags);

return ret;
}
Expand All @@ -263,10 +249,10 @@ void add_timer_on(struct timer_list *timer, int cpu)
unsigned long flags;

BUG_ON(timer_pending(timer) || !timer->function);
spin_lock_irqsave(&base->t_base.lock, flags);
timer->base = &base->t_base;
spin_lock_irqsave(&base->lock, flags);
timer->base = base;
internal_add_timer(base, timer);
spin_unlock_irqrestore(&base->t_base.lock, flags);
spin_unlock_irqrestore(&base->lock, flags);
}


Expand Down Expand Up @@ -319,7 +305,7 @@ EXPORT_SYMBOL(mod_timer);
*/
int del_timer(struct timer_list *timer)
{
timer_base_t *base;
tvec_base_t *base;
unsigned long flags;
int ret = 0;

Expand All @@ -346,7 +332,7 @@ EXPORT_SYMBOL(del_timer);
*/
int try_to_del_timer_sync(struct timer_list *timer)
{
timer_base_t *base;
tvec_base_t *base;
unsigned long flags;
int ret = -1;

Expand Down Expand Up @@ -410,7 +396,7 @@ static int cascade(tvec_base_t *base, tvec_t *tv, int index)
struct timer_list *tmp;

tmp = list_entry(curr, struct timer_list, entry);
BUG_ON(tmp->base != &base->t_base);
BUG_ON(tmp->base != base);
curr = curr->next;
internal_add_timer(base, tmp);
}
Expand All @@ -432,7 +418,7 @@ static inline void __run_timers(tvec_base_t *base)
{
struct timer_list *timer;

spin_lock_irq(&base->t_base.lock);
spin_lock_irq(&base->lock);
while (time_after_eq(jiffies, base->timer_jiffies)) {
struct list_head work_list = LIST_HEAD_INIT(work_list);
struct list_head *head = &work_list;
Expand All @@ -458,7 +444,7 @@ static inline void __run_timers(tvec_base_t *base)

set_running_timer(base, timer);
detach_timer(timer, 1);
spin_unlock_irq(&base->t_base.lock);
spin_unlock_irq(&base->lock);
{
int preempt_count = preempt_count();
fn(data);
Expand All @@ -471,11 +457,11 @@ static inline void __run_timers(tvec_base_t *base)
BUG();
}
}
spin_lock_irq(&base->t_base.lock);
spin_lock_irq(&base->lock);
}
}
set_running_timer(base, NULL);
spin_unlock_irq(&base->t_base.lock);
spin_unlock_irq(&base->lock);
}

#ifdef CONFIG_NO_IDLE_HZ
Expand Down Expand Up @@ -506,7 +492,7 @@ unsigned long next_timer_interrupt(void)
hr_expires += jiffies;

base = __get_cpu_var(tvec_bases);
spin_lock(&base->t_base.lock);
spin_lock(&base->lock);
expires = base->timer_jiffies + (LONG_MAX >> 1);
list = NULL;

Expand Down Expand Up @@ -554,7 +540,7 @@ unsigned long next_timer_interrupt(void)
expires = nte->expires;
}
}
spin_unlock(&base->t_base.lock);
spin_unlock(&base->lock);

if (time_before(hr_expires, expires))
return hr_expires;
Expand Down Expand Up @@ -1262,7 +1248,7 @@ static int __devinit init_timers_cpu(int cpu)
}
per_cpu(tvec_bases, cpu) = base;
}
spin_lock_init(&base->t_base.lock);
spin_lock_init(&base->lock);
for (j = 0; j < TVN_SIZE; j++) {
INIT_LIST_HEAD(base->tv5.vec + j);
INIT_LIST_HEAD(base->tv4.vec + j);
Expand All @@ -1284,7 +1270,7 @@ static void migrate_timer_list(tvec_base_t *new_base, struct list_head *head)
while (!list_empty(head)) {
timer = list_entry(head->next, struct timer_list, entry);
detach_timer(timer, 0);
timer->base = &new_base->t_base;
timer->base = new_base;
internal_add_timer(new_base, timer);
}
}
Expand All @@ -1300,11 +1286,11 @@ static void __devinit migrate_timers(int cpu)
new_base = get_cpu_var(tvec_bases);

local_irq_disable();
spin_lock(&new_base->t_base.lock);
spin_lock(&old_base->t_base.lock);
spin_lock(&new_base->lock);
spin_lock(&old_base->lock);

BUG_ON(old_base->running_timer);

if (old_base->t_base.running_timer)
BUG();
for (i = 0; i < TVR_SIZE; i++)
migrate_timer_list(new_base, old_base->tv1.vec + i);
for (i = 0; i < TVN_SIZE; i++) {
Expand All @@ -1314,8 +1300,8 @@ static void __devinit migrate_timers(int cpu)
migrate_timer_list(new_base, old_base->tv5.vec + i);
}

spin_unlock(&old_base->t_base.lock);
spin_unlock(&new_base->t_base.lock);
spin_unlock(&old_base->lock);
spin_unlock(&new_base->lock);
local_irq_enable();
put_cpu_var(tvec_bases);
}
Expand Down

0 comments on commit 3691c51

Please sign in to comment.