Date: Mon, 20 Apr 2009 03:44:54 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/mips/mips pmap.c Message-ID: <200904200345.n3K3j81C059655@repoman.freebsd.org>
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alc 2009-04-20 03:44:54 UTC
FreeBSD src repository
Modified files:
sys/mips/mips pmap.c
Log:
SVN rev 191300 on 2009-04-20 03:44:54Z by alc
MFamd64/i386
Introduce pmap_try_insert_pv_entry(), a function that conditionally
creates a pv entry if the number of entries is below the high water mark
for pv entries.
Introduce pmap_enter_quick_locked() and use it to reimplement
pmap_enter_object(). The old implementation was broken. For example,
it could block while holding a mutex lock.
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.
Tested by: gonzo
Revision Changes Path
1.14 +70 -39 src/sys/mips/mips/pmap.c
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