Module Name: src
Committed By: yamt
Date: Mon Jun 1 22:04:54 UTC 2009
Modified Files:
src/lib/libc/sys: madvise.2
Log Message:
don't describe internal details.
To generate a diff of this commit:
cvs rdiff -u -r1.24 -r1.25 src/lib/libc/sys/madvise.2
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/sys/madvise.2
diff -u src/lib/libc/sys/madvise.2:1.24 src/lib/libc/sys/madvise.2:1.25
--- src/lib/libc/sys/madvise.2:1.24 Tue Apr 22 10:42:16 2008
+++ src/lib/libc/sys/madvise.2 Mon Jun 1 22:04:54 2009
@@ -1,4 +1,4 @@
-.\" $NetBSD: madvise.2,v 1.24 2008/04/22 10:42:16 rmind Exp $
+.\" $NetBSD: madvise.2,v 1.25 2009/06/01 22:04:54 yamt Exp $
.\"
.\" Copyright (c) 1991, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -29,7 +29,7 @@
.\"
.\" @(#)madvise.2 8.1 (Berkeley) 6/9/93
.\"
-.Dd April 19, 2008
+.Dd June 2, 2009
.Dt MADVISE 2
.Os
.Sh NAME
@@ -62,24 +62,23 @@
Is a hint that pages will be accessed randomly, and prefetching
is likely not advantageous.
.It Dv MADV_SEQUENTIAL
-Causes the VM system to depress the priority of
+Is a hint that pages will be accessed sequentially, from the lower address to
+higher address.
+It might cause the VM system to depress the priority of
pages immediately preceding a given page when it is faulted in.
.It Dv MADV_WILLNEED
-Causes pages that are in a given virtual address range
-to temporarily have higher priority, and if they are in
+Is a hint that pages will be accessed in the near future.
+It might cause the VM system to make pages that are in a given virtual
+address range to temporarily have higher priority, and if they are in
memory, decrease the likelihood of them being freed.
-Additionally,
-the pages that are already in memory will be immediately mapped into
-the process, thereby eliminating unnecessary overhead of going through
+It might immediately map the pages that are already in memory into the
+process, thereby eliminating unnecessary overhead of going through
the entire process of faulting the pages in.
-This WILL NOT fault
-pages in from backing store, but quickly map the pages already in memory
-into the calling process.
+It might or might not fault pages in from backing store.
.It Dv MADV_DONTNEED
-Allows the VM system to decrease the in-memory priority
+Is a hint that pages will not be accessed in the near future.
+It might allow the VM system to decrease the in-memory priority
of pages in the specified range.
-Additionally future references to
-this address range will incur a page fault.
.It Dv MADV_FREE
Gives the VM system the freedom to free pages,
and tells the system that information in the specified page range
