Differential D20545 Diff 58407 head/sys/vm/swap_pager.c

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head/sys/vm/swap_pager.c

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int		int
swap_pager_nswapdev(void)		swap_pager_nswapdev(void)
{		{

return (nswapdev);		return (nswapdev);
}		}

		static void
		swp_pager_force_dirty(vm_page_t m)
		{

		vm_page_dirty(m);
		#ifdef INVARIANTS
		vm_page_lock(m);
		if (!vm_page_wired(m) && m->queue == PQ_NONE)
		panic("page %p is neither wired nor queued", m);
		vm_page_unlock(m);
		#endif
		vm_page_xunbusy(m);
		}

		static void
		swp_pager_force_launder(vm_page_t m)
		{

		vm_page_dirty(m);
		vm_page_lock(m);
		vm_page_launder(m);
		vm_page_unlock(m);
		vm_page_xunbusy(m);
		}

/*		/*
* SWP_PAGER_FORCE_PAGEIN() - force a swap block to be paged in		* SWP_PAGER_FORCE_PAGEIN() - force a swap block to be paged in
*		*
* This routine dissociates the page at the given index within an object		* This routine dissociates the page at the given index within an object
* from its backing store, paging it in if it does not reside in memory.		* from its backing store, paging it in if it does not reside in memory.
* If the page is paged in, it is marked dirty and placed in the laundry		* If the page is paged in, it is marked dirty and placed in the laundry
* queue. The page is marked dirty because it no longer has backing		* queue. The page is marked dirty because it no longer has backing
* store. It is placed in the laundry queue because it has not been		* store. It is placed in the laundry queue because it has not been
* accessed recently. Otherwise, it would already reside in memory.		* accessed recently. Otherwise, it would already reside in memory.
*		*
* We also attempt to swap in all other pages in the swap block.		* We also attempt to swap in all other pages in the swap block.
* However, we only guarantee that the one at the specified index is		* However, we only guarantee that the one at the specified index is
* paged in.		* paged in.
*		*
* XXX - The code to page the whole block in doesn't work, so we		* XXX - The code to page the whole block in doesn't work, so we
* revert to the one-by-one behavior for now. Sigh.		* revert to the one-by-one behavior for now. Sigh.
*/		*/
static inline void		static void
swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex)		swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex)
{		{
vm_page_t m;		vm_page_t m;

vm_object_pip_add(object, 1);		vm_object_pip_add(object, 1);
m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);		m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);
if (m->valid == VM_PAGE_BITS_ALL) {		if (m->valid == VM_PAGE_BITS_ALL) {
vm_object_pip_wakeup(object);		vm_object_pip_wakeup(object);
vm_page_dirty(m);		swp_pager_force_dirty(m);
#ifdef INVARIANTS
vm_page_lock(m);
if (!vm_page_wired(m) && m->queue == PQ_NONE)
panic("page %p is neither wired nor queued", m);
vm_page_unlock(m);
#endif
vm_page_xunbusy(m);
vm_pager_page_unswapped(m);		vm_pager_page_unswapped(m);
return;		return;
}		}

if (swap_pager_getpages(object, &m, 1, NULL, NULL) != VM_PAGER_OK)		if (swap_pager_getpages(object, &m, 1, NULL, NULL) != VM_PAGER_OK)
panic("swap_pager_force_pagein: read from swap failed");/XXX/		panic("swap_pager_force_pagein: read from swap failed");/XXX/
vm_object_pip_wakeup(object);		vm_object_pip_wakeup(object);
vm_page_dirty(m);		swp_pager_force_launder(m);
vm_page_lock(m);
vm_page_launder(m);
vm_page_unlock(m);
vm_page_xunbusy(m);
vm_pager_page_unswapped(m);		vm_pager_page_unswapped(m);
}		}

/*		/*
		* swap_pager_swapoff_object:
		*
		* Page in all of the pages that have been paged out for an object
		* from a given swap device.
		*/
		static void
		swap_pager_swapoff_object(struct swdevt *sp, vm_object_t object)
		{
		struct swblk *sb;
		vm_pindex_t pi;
		int i;

		for (pi = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(
		&object->un_pager.swp.swp_blks, pi)) != NULL; ) {
		pi = sb->p + SWAP_META_PAGES;
		for (i = 0; i < SWAP_META_PAGES; i++) {
		if (sb->d[i] == SWAPBLK_NONE)
		continue;
		if (swp_pager_isondev(sb->d[i], sp))
		swp_pager_force_pagein(object, sb->p + i);
		}
		}
		}

		/*
* swap_pager_swapoff:		* swap_pager_swapoff:
*		*
* Page in all of the pages that have been paged out to the		* Page in all of the pages that have been paged out to the
* given device. The corresponding blocks in the bitmap must be		* given device. The corresponding blocks in the bitmap must be
* marked as allocated and the device must be flagged SW_CLOSING.		* marked as allocated and the device must be flagged SW_CLOSING.
* There may be no processes swapped out to the device.		* There may be no processes swapped out to the device.
*		*
* This routine may block.		* This routine may block.
*/		*/
static void		static void
swap_pager_swapoff(struct swdevt *sp)		swap_pager_swapoff(struct swdevt *sp)
{		{
struct swblk *sb;
vm_object_t object;		vm_object_t object;
vm_pindex_t pi;		int retries;
int i, retries;

sx_assert(&swdev_syscall_lock, SA_XLOCKED);		sx_assert(&swdev_syscall_lock, SA_XLOCKED);

retries = 0;		retries = 0;
full_rescan:		full_rescan:
mtx_lock(&vm_object_list_mtx);		mtx_lock(&vm_object_list_mtx);
TAILQ_FOREACH(object, &vm_object_list, object_list) {		TAILQ_FOREACH(object, &vm_object_list, object_list) {
if (object->type != OBJT_SWAP)		if (object->type != OBJT_SWAP)
Show All 13 Lines	TAILQ_FOREACH(object, &vm_object_list, object_list) {
* initialization. We must not access pctrie below		* initialization. We must not access pctrie below
* unless we checked that our object is swap and not		* unless we checked that our object is swap and not
* dead.		* dead.
*/		*/
atomic_thread_fence_acq();		atomic_thread_fence_acq();
if (object->type != OBJT_SWAP)		if (object->type != OBJT_SWAP)
goto next_obj;		goto next_obj;

for (pi = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(		swap_pager_swapoff_object(sp, object);
&object->un_pager.swp.swp_blks, pi)) != NULL; ) {
pi = sb->p + SWAP_META_PAGES;
for (i = 0; i < SWAP_META_PAGES; i++) {
if (sb->d[i] == SWAPBLK_NONE)
continue;
if (swp_pager_isondev(sb->d[i], sp))
swp_pager_force_pagein(object,
sb->p + i);
}
}
next_obj:		next_obj:
VM_OBJECT_WUNLOCK(object);		VM_OBJECT_WUNLOCK(object);
mtx_lock(&vm_object_list_mtx);		mtx_lock(&vm_object_list_mtx);
}		}
mtx_unlock(&vm_object_list_mtx);		mtx_unlock(&vm_object_list_mtx);

if (sp->sw_used) {		if (sp->sw_used) {
/*		/*
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