linux-2.6.33/kswapd()
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開始行:
*参照元 [#g2e98dfa]
#backlinks
*説明 [#y25f1d77]
-パス: [[linux-2.6.33/mm/vmscan.c]]
-FIXME: これは何？
--説明
**引数 [#l36f6121]
-void *p
--pg_data_t のポインタをキャストした値が渡される。
--[[linux-2.6.33/pg_data_t]]
**返り値 [#x6010da3]
-int
--
**参考 [#ced0da59]
*実装 [#p31faeaf]
/*
* The background pageout daemon, started as a kernel th...
* from the init process.
*
* This basically trickles out pages so that we have _so...
* free memory available even if there is no other activ...
* that frees anything up. This is needed for things lik...
* etc, where we otherwise might have all activity going...
* asynchronous contexts that cannot page things out.
*
* If there are applications that are active memory-allo...
* (most normal use), this basically shouldn't matter.
*/
static int kswapd(void *p)
{
unsigned long order;
pg_data_t *pgdat = (pg_data_t*)p;
struct task_struct *tsk = current;
DEFINE_WAIT(wait);
struct reclaim_state reclaim_state = {
.reclaimed_slab = 0,
};
const struct cpumask *cpumask = cpumask_of_node(pgdat->...
-
--[[linux-2.6.33/task_struct]]
-
--[[linux-2.6.33/current(global)]]
-
--[[linux-2.6.33/DEFINE_WAIT()]]
-
--[[linux-2.6.33/reclaim_state]]
-
--[[linux-2.6.33/cpumask]]
-
--[[linux-2.6.33/cpumask_of_node()]]
lockdep_set_current_reclaim_state(GFP_KERNEL);
-
--[[linux-2.6.33/lockdep_set_current_relcaim_state()]]
-
--[[linux-2.6.33/GFP_KERNEL]]
if (!cpumask_empty(cpumask))
set_cpus_allowed_ptr(tsk, cpumask);
current->reclaim_state = &reclaim_state;
-
--[[linux-2.6.33/cpumask_empty()]]
-
--[[linux-2.6.33/set_cpus_allowed_ptr()]]
/*
* Tell the memory management that we're a "memory allo...
* and that if we need more memory we should get access...
* regardless (see "__alloc_pages()"). "kswapd" should
* never get caught in the normal page freeing logic.
*
* (Kswapd normally doesn't need memory anyway, but som...
* you need a small amount of memory in order to be abl...
* page out something else, and this flag essentially p...
* us from recursively trying to free more memory as we...
* trying to free the first piece of memory in the firs...
*/
tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
set_freezable();
-
--[[linux-2.6.33/PF_MEMALLOC]]
-
--[[linux-2.6.33/PF_SWAPWRITE]]
-
--[[linux-2.6.33/PF_KSWAPD]]
-
--[[linux-2.6.33/set_freezable()]]
order = 0;
for ( ; ; ) {
unsigned long new_order;
int ret;
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTER...
new_order = pgdat->kswapd_max_order;
pgdat->kswapd_max_order = 0;
-
--[[linux-2.6.33/prepare_to_wait()]]
-
--[[linux-2.6.33/TASK_INTERRUPTIBLE]]
if (order < new_order) {
/*
* Don't sleep if someone wants a larger 'order'
* allocation
*/
order = new_order;
} else {
if (!freezing(current) && !kthread_should_stop()) {
long remaining = 0;
-
--[[linux-2.6.33/freezing()]]
-
--[[linux-2.6.33/kthread_should_stop()]]
/* Try to sleep for a short interval */
if (!sleeping_prematurely(pgdat, order, remaining)) {
-
--[[linux-2.6.33/sleeping_prematurely()]]
remaining = schedule_timeout(HZ/10);
finish_wait(&pgdat->kswapd_wait, &wait);
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_IN...
-
--[[linux-2.6.33/schedule_timeout()]]
-
--[[linux-2.6.33/finish_wait()]]
-
--[[linux-2.6.33/prepare_to_wait()]]
}
/*
* After a short sleep, check if it was a
* premature sleep. If not, then go fully
* to sleep until explicitly woken up
*/
if (!sleeping_prematurely(pgdat, order, remaining))
schedule();
-
--[[linux-2.6.33/schedule()]]
else {
if (remaining)
count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
else
count_vm_event(KSWAPD_HIGH_WMARK_HIT_QUICKLY);
-
--[[linux-2.6.33/count_vm_event()]]
-
--[[linux-2.6.33/KSWAPD_LOW_WMARK_HIT_QUICKLY]]
-
--[[linux-2.6.33/KSWAPD_HIGH_WMARK_HIT_QUICKLY]]
}
}
order = pgdat->kswapd_max_order;
}
finish_wait(&pgdat->kswapd_wait, &wait);
-
--[[linux-2.6.33/finish_wait()]]
ret = try_to_freeze();
if (kthread_should_stop())
break;
-
--[[linux-2.6.33/try_to_freeze()]]
/*
* We can speed up thawing tasks if we don't call bala...
* after returning from the refrigerator
*/
if (!ret)
balance_pgdat(pgdat, order);
-
--[[linux-2.6.33/balance_pgdat()]]
}
return 0;
}
*コメント [#g26696a6]
終了行:
*参照元 [#g2e98dfa]
#backlinks
*説明 [#y25f1d77]
-パス: [[linux-2.6.33/mm/vmscan.c]]
-FIXME: これは何？
--説明
**引数 [#l36f6121]
-void *p
--pg_data_t のポインタをキャストした値が渡される。
--[[linux-2.6.33/pg_data_t]]
**返り値 [#x6010da3]
-int
--
**参考 [#ced0da59]
*実装 [#p31faeaf]
/*
* The background pageout daemon, started as a kernel th...
* from the init process.
*
* This basically trickles out pages so that we have _so...
* free memory available even if there is no other activ...
* that frees anything up. This is needed for things lik...
* etc, where we otherwise might have all activity going...
* asynchronous contexts that cannot page things out.
*
* If there are applications that are active memory-allo...
* (most normal use), this basically shouldn't matter.
*/
static int kswapd(void *p)
{
unsigned long order;
pg_data_t *pgdat = (pg_data_t*)p;
struct task_struct *tsk = current;
DEFINE_WAIT(wait);
struct reclaim_state reclaim_state = {
.reclaimed_slab = 0,
};
const struct cpumask *cpumask = cpumask_of_node(pgdat->...
-
--[[linux-2.6.33/task_struct]]
-
--[[linux-2.6.33/current(global)]]
-
--[[linux-2.6.33/DEFINE_WAIT()]]
-
--[[linux-2.6.33/reclaim_state]]
-
--[[linux-2.6.33/cpumask]]
-
--[[linux-2.6.33/cpumask_of_node()]]
lockdep_set_current_reclaim_state(GFP_KERNEL);
-
--[[linux-2.6.33/lockdep_set_current_relcaim_state()]]
-
--[[linux-2.6.33/GFP_KERNEL]]
if (!cpumask_empty(cpumask))
set_cpus_allowed_ptr(tsk, cpumask);
current->reclaim_state = &reclaim_state;
-
--[[linux-2.6.33/cpumask_empty()]]
-
--[[linux-2.6.33/set_cpus_allowed_ptr()]]
/*
* Tell the memory management that we're a "memory allo...
* and that if we need more memory we should get access...
* regardless (see "__alloc_pages()"). "kswapd" should
* never get caught in the normal page freeing logic.
*
* (Kswapd normally doesn't need memory anyway, but som...
* you need a small amount of memory in order to be abl...
* page out something else, and this flag essentially p...
* us from recursively trying to free more memory as we...
* trying to free the first piece of memory in the firs...
*/
tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
set_freezable();
-
--[[linux-2.6.33/PF_MEMALLOC]]
-
--[[linux-2.6.33/PF_SWAPWRITE]]
-
--[[linux-2.6.33/PF_KSWAPD]]
-
--[[linux-2.6.33/set_freezable()]]
order = 0;
for ( ; ; ) {
unsigned long new_order;
int ret;
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTER...
new_order = pgdat->kswapd_max_order;
pgdat->kswapd_max_order = 0;
-
--[[linux-2.6.33/prepare_to_wait()]]
-
--[[linux-2.6.33/TASK_INTERRUPTIBLE]]
if (order < new_order) {
/*
* Don't sleep if someone wants a larger 'order'
* allocation
*/
order = new_order;
} else {
if (!freezing(current) && !kthread_should_stop()) {
long remaining = 0;
-
--[[linux-2.6.33/freezing()]]
-
--[[linux-2.6.33/kthread_should_stop()]]
/* Try to sleep for a short interval */
if (!sleeping_prematurely(pgdat, order, remaining)) {
-
--[[linux-2.6.33/sleeping_prematurely()]]
remaining = schedule_timeout(HZ/10);
finish_wait(&pgdat->kswapd_wait, &wait);
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_IN...
-
--[[linux-2.6.33/schedule_timeout()]]
-
--[[linux-2.6.33/finish_wait()]]
-
--[[linux-2.6.33/prepare_to_wait()]]
}
/*
* After a short sleep, check if it was a
* premature sleep. If not, then go fully
* to sleep until explicitly woken up
*/
if (!sleeping_prematurely(pgdat, order, remaining))
schedule();
-
--[[linux-2.6.33/schedule()]]
else {
if (remaining)
count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
else
count_vm_event(KSWAPD_HIGH_WMARK_HIT_QUICKLY);
-
--[[linux-2.6.33/count_vm_event()]]
-
--[[linux-2.6.33/KSWAPD_LOW_WMARK_HIT_QUICKLY]]
-
--[[linux-2.6.33/KSWAPD_HIGH_WMARK_HIT_QUICKLY]]
}
}
order = pgdat->kswapd_max_order;
}
finish_wait(&pgdat->kswapd_wait, &wait);
-
--[[linux-2.6.33/finish_wait()]]
ret = try_to_freeze();
if (kthread_should_stop())
break;
-
--[[linux-2.6.33/try_to_freeze()]]
/*
* We can speed up thawing tasks if we don't call bala...
* after returning from the refrigerator
*/
if (!ret)
balance_pgdat(pgdat, order);
-
--[[linux-2.6.33/balance_pgdat()]]
}
return 0;
}
*コメント [#g26696a6]
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