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Micro-optimize the handling of fictitious pages in vm_page_free_prep().

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A fictitious page is always wired, so there is no point in trying to
remove one from the page queues.

Completely remove one inaccurate comment from vm_page_free_prep() and
correct another.

Reviewed by:	kib, markj
MFC after:	1 week
This commit is contained in:
Alan Cox 2017-10-24 17:14:53 +00:00
parent d27927f731
commit 3a757e5403
1 changed files with 12 additions and 13 deletions
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25
sys/vm/vm_page.c
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@ -2802,27 +2802,26 @@ vm_page_free_prep(vm_page_t m, bool pagequeue_locked)
if (vm_page_sbusied(m))
panic("vm_page_free: freeing busy page %p", m);
vm_page_remove(m);
/*
* Unqueue, then remove page. Note that we cannot destroy
* the page here because we do not want to call the pager's
* callback routine until after we've put the page on the
* appropriate free queue.
* If fictitious remove object association and
* return.
*/
if ((m->flags & PG_FICTITIOUS) != 0) {
KASSERT(m->wire_count == 1,
("fictitious page %p is not wired", m));
KASSERT(m->queue == PQ_NONE,
("fictitious page %p is queued", m));
return (false);
}
if (m->queue != PQ_NONE) {
if (pagequeue_locked)
vm_page_dequeue_locked(m);
else
vm_page_dequeue(m);
}
vm_page_remove(m);
/*
* If fictitious remove object association and
* return, otherwise delay object association removal.
*/
if ((m->flags & PG_FICTITIOUS) != 0)
return (false);
m->valid = 0;
vm_page_undirty(m);