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Restructure vm_page_select_cache() so that adding assertions is easy.

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Some of the conditions that caused vm_page_select_cache() to deactivate a
page were wrong.  For example, deactivating an unmanaged or wired page is a
nop.  Thus, if vm_page_select_cache() had ever encountered an unmanaged or
wired page, it would have looped forever.  Now, we assert that the page is
neither unmanaged nor wired.
This commit is contained in:
alc 2004-05-12 04:27:18 +00:00
parent 14bc83bc9c
commit 625c8dfb26
1 changed files with 15 additions and 10 deletions
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25
sys/vm/vm_page.c
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@ -708,17 +708,23 @@ vm_page_select_cache(int color)
vm_page_t m;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
while (TRUE) {
m = vm_pageq_find(PQ_CACHE, color, FALSE);
if (m && ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy ||
m->hold_count || m->wire_count ||
(!VM_OBJECT_TRYLOCK(m->object) &&
!VM_OBJECT_LOCKED(m->object)))) {
vm_page_deactivate(m);
continue;
while ((m = vm_pageq_find(PQ_CACHE, color, FALSE)) != NULL) {
if ((m->flags & PG_BUSY) == 0 && m->busy == 0 &&
m->hold_count == 0 && (VM_OBJECT_TRYLOCK(m->object) ||
VM_OBJECT_LOCKED(m->object))) {
KASSERT(m->dirty == 0,
("Found dirty cache page %p", m));
KASSERT(!pmap_page_is_mapped(m),
("Found mapped cache page %p", m));
KASSERT((m->flags & PG_UNMANAGED) == 0,
("Found unmanaged cache page %p", m));
KASSERT(m->wire_count == 0,
("Found wired cache page %p", m));
break;
}
return m;
vm_page_deactivate(m);
}
return (m);
}
/*
@ -795,7 +801,6 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
pagedaemon_wakeup();
return (NULL);
}
KASSERT(m->dirty == 0, ("Found dirty cache page %p", m));
m_object = m->object;
VM_OBJECT_LOCK_ASSERT(m_object, MA_OWNED);
vm_page_busy(m);