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authorHiroki Sato <hrs@FreeBSD.org>2009-04-30 21:20:09 +0000
committerHiroki Sato <hrs@FreeBSD.org>2009-04-30 21:20:09 +0000
commit510c6cf29a128c3504341a84ee778f6ce9de01d1 (patch)
treed71318275812c9ae3148e3d9c1bd303eae8b5c75
parentc998438538bcb6edcac132db994a82fd851f3e44 (diff)
downloadsrc-510c6cf29a128c3504341a84ee778f6ce9de01d1.tar.gz
src-510c6cf29a128c3504341a84ee778f6ce9de01d1.zip
Revise entry for superpages.
Suggested by: rwatson Approved by: re (implicit)
Notes
Notes: svn path=/releng/7.2/; revision=191705
-rw-r--r--release/doc/en_US.ISO8859-1/relnotes/article.sgml19
1 files changed, 10 insertions, 9 deletions
diff --git a/release/doc/en_US.ISO8859-1/relnotes/article.sgml b/release/doc/en_US.ISO8859-1/relnotes/article.sgml
index cde6e6215b1a..37aeb3069362 100644
--- a/release/doc/en_US.ISO8859-1/relnotes/article.sgml
+++ b/release/doc/en_US.ISO8859-1/relnotes/article.sgml
@@ -296,15 +296,16 @@
<literal>VFS_AIO</literal>.</para>
<para arch="amd64,i386">The &os; virtual memory subsystem now
- supports <application>Superpages</application>. The
- <application>Superpages</application> is a feature that
- enables each entry in the TLB (translation lookaside buffer)
- to map a large physical memory region into a virtual address
- space in modern CPUs. This provides possible memory savings
- for applications that share large amounts of memory between
- the address spaces and performance improvements due to fewer
- TLB misses. This is disabled by default and can be enabled by
- setting a loader tunable
+ supports fully transparent use of
+ <application>superpages</application> for application memory;
+ application memory pages are dynamically promoted to or
+ demoted from superpages without any modification to
+ application code. This change offers the benefit of large
+ page sizes such as improved virtual memory efficiency and
+ reduced TLB (translation lookaside buffer) misses without
+ downsides like application changes and virtual memory
+ inflexibility. This is disabled by default and can be enabled
+ by setting a loader tunable
<varname>vm.pmap.pg_ps_enabled</varname> to
<literal>1</literal>.</para>