Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

don't describe internal details.

This commit is contained in:
yamt 2009-06-01 22:04:54 +00:00
parent 476755a88c
commit cef9767a7a
1 changed files with 13 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
lib/libc/sys/madvise.2
View File

@ -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 @@ behavior.
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