Date: Sat, 24 Apr 2010 17:32:52 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/amd64/amd64 pmap.c src/sys/arm/arm pmap.c src/sys/i386/i386 pmap.c src/sys/i386/xen pmap.c src/sys/ia64/ia64 pmap.c src/sys/mips/mips pmap.c src/sys/powerpc/aim mmu_oea.c mmu_oea64.c src/sys/powerpc/booke pmap.c src/sys/powerpc/powerpc ... Message-ID: <201004241737.o3OHbRP7050212@repoman.freebsd.org>
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alc 2010-04-24 17:32:52 UTC
FreeBSD src repository
Modified files:
sys/amd64/amd64 pmap.c
sys/arm/arm pmap.c
sys/i386/i386 pmap.c
sys/i386/xen pmap.c
sys/ia64/ia64 pmap.c
sys/mips/mips pmap.c
sys/powerpc/aim mmu_oea.c mmu_oea64.c
sys/powerpc/booke pmap.c
sys/powerpc/powerpc mmu_if.m pmap_dispatch.c
sys/sparc64/sparc64 pmap.c
sys/sun4v/sun4v pmap.c
sys/vm pmap.h vm_mmap.c
Log:
SVN rev 207155 on 2010-04-24 17:32:52Z by alc
Resurrect pmap_is_referenced() and use it in mincore(). Essentially,
pmap_ts_referenced() is not always appropriate for checking whether or
not pages have been referenced because it clears any reference bits
that it encounters. For example, in mincore(), clearing the reference
bits has two negative consequences. First, it throws off the activity
count calculations performed by the page daemon. Specifically, a page
on which mincore() has called pmap_ts_referenced() looks less active
to the page daemon than it should. Consequently, the page could be
deactivated prematurely by the page daemon. Arguably, this problem
could be fixed by having mincore() duplicate the activity count
calculation on the page. However, there is a second problem for which
that is not a solution. In order to clear a reference on a 4KB page,
it may be necessary to demote a 2/4MB page mapping. Thus, a mincore()
by one process can have the side effect of demoting a superpage
mapping within another process!
Revision Changes Path
1.689 +45 -3 src/sys/amd64/amd64/pmap.c
1.120 +14 -0 src/sys/arm/arm/pmap.c
1.671 +47 -3 src/sys/i386/i386/pmap.c
1.34 +29 -3 src/sys/i386/xen/pmap.c
1.214 +32 -3 src/sys/ia64/ia64/pmap.c
1.41 +15 -3 src/sys/mips/mips/pmap.c
1.135 +11 -0 src/sys/powerpc/aim/mmu_oea.c
1.22 +11 -0 src/sys/powerpc/aim/mmu_oea64.c
1.23 +29 -0 src/sys/powerpc/booke/pmap.c
1.13 +14 -0 src/sys/powerpc/powerpc/mmu_if.m
1.21 +8 -0 src/sys/powerpc/powerpc/pmap_dispatch.c
1.188 +21 -0 src/sys/sparc64/sparc64/pmap.c
1.49 +11 -0 src/sys/sun4v/sun4v/pmap.c
1.89 +1 -0 src/sys/vm/pmap.h
1.238 +1 -3 src/sys/vm/vm_mmap.c
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