Date: Tue, 20 Jun 2006 20:52:11 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/amd64/amd64 pmap.c src/sys/i386/i386 pmap.c Message-ID: <200606202052.k5KKqBCc071633@repoman.freebsd.org>
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alc 2006-06-20 20:52:11 UTC
FreeBSD src repository
Modified files:
sys/amd64/amd64 pmap.c
sys/i386/i386 pmap.c
Log:
Change get_pv_entry() such that the call to vm_page_alloc() specifies
VM_ALLOC_NORMAL instead of VM_ALLOC_SYSTEM when try is TRUE. In other
words, when get_pv_entry() is permitted to fail, it no longer tries as
hard to allocate a page.
Change pmap_enter_quick_locked() to fail rather than wait if it is
unable to allocate a page table page. This prevents a race between
pmap_enter_object() and the page daemon. Specifically, an inactive
page that is a successor to the page that was given to
pmap_enter_quick_locked() might become a cache page while
pmap_enter_quick_locked() waits and later pmap_enter_object() maps
the cache page violating the invariant that cache pages are never
mapped. Similarly, change
pmap_enter_quick_locked() to call pmap_try_insert_pv_entry() rather
than pmap_insert_entry(). Generally speaking,
pmap_enter_quick_locked() is used to create speculative mappings. So,
it should not try hard to allocate memory if free memory is scarce.
Add an assertion that the object containing m_start is locked in
pmap_enter_object(). Remove a similar assertion from
pmap_enter_quick_locked() because that function no longer accesses the
containing object.
Remove a stale comment.
Reviewed by: ups@
Revision Changes Path
1.558 +15 -21 src/sys/amd64/amd64/pmap.c
1.562 +15 -21 src/sys/i386/i386/pmap.c
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