Date: Sat, 31 Mar 2007 22:13:26 +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/i386/i386 pmap.c Message-ID: <200703312213.l2VMDQFG093183@repoman.freebsd.org>
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alc 2007-03-31 22:13:26 UTC
FreeBSD src repository
Modified files: (Branch: RELENG_6)
sys/i386/i386 pmap.c
Log:
MFC revision 1.559
Introduce the function pmap_enter_object().
MFC revision 1.562 (in part)
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.
Revision Changes Path
1.523.2.16 +59 -24 src/sys/i386/i386/pmap.c
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