On Wed, Mar 15, 2000 at 10:24:27AM -0800, Richard Henderson wrote:
> On Wed, Mar 15, 2000 at 07:16:48PM +0100, Andrea Arcangeli wrote:
> > Do you know how the madvise syscall works on OSF/1? That matters to be
> > binary compatible.
>
> #define MADV_NORMAL 0 /* no further special treatment */
> #define MADV_RANDOM 1 /* expect random page references */
> #define MADV_SEQUENTIAL 2 /* expect sequential page references */
> #define MADV_WILLNEED 3 /* will need these pages */
> #define MADV_DONTNEED_COMPAT 4 /* for backward compatibility */
> #define MADV_SPACEAVAIL 5 /* ensure resources are available */
> #define MADV_DONTNEED 6 /* dont need these pages */
>
> Dunno what the difference between 4 and 6 are.
>
>
> r~
>
Here's what I found on a DU 4.0 system:
madvise(2) madvise(2)
NAME
madvise - Advise the system of the expected paging behavior of a process
SYNOPSIS
#include <sys/types.h>
#include <sys/mman.h>
int madvise (
caddr_t addr,
size_t len,
int behav );
PARAMETERS
addr Specifies the address of the region to which the advice refers.
len Specifies the length in bytes of the region specified by the addr
parameter.
behav Specifies the behavior of the region. The following values for
the behav parameter are defined in the sys/mman.h header file:
MADV_NORMAL
No further special treatment
MADV_RANDOM
Expect random page references
MADV_SEQUENTIAL
Expect sequential references
MADV_WILLNEED
Will need these pages
MADV_DONTNEED
Do not need these pages
The system will free any whole pages in the specified
region. All modifications will be lost and any swapped
out pages will be discarded. Subsequent access to the
region will result in a zero-fill-on-demand fault as
though it is being accessed for the first time.
Reserved swap space is not affected by this call.
MADV_SPACEAVAIL
Ensure that resources are reserved
DESCRIPTION
The madvise() function permits a process to advise the system about its
expected future behavior in referencing a mapped file or shared memory
region.
NOTES
Only a few values of the behav parameter values are operational on Tru64
UNIX systems. Non-operational values cause the system to always return
success (zero).
RETURN VALUES
Upon successful completion, the madvise() function returns zero. Other-
wise, -1 is returned and errno is set to indicate the error.
ERRORS
If the madvise() function fails, errno may be set to one of the following
values:
[EINVAL] The behav parameter is invalid.
[ENOSPC] The behav parameter specifies MADV_SPACEAVAIL and resources can-
not be reserved.
RELATED INFORMATION
Functions: mmap(2)
--Jay++
-----------------------------------------------------------------------------
Jay A Estabrook Alpha Engineering - LINUX Project
Compaq Computer Corp. - MRO1-2/K20 (508) 467-2080
200 Forest Street, Marlboro MA 01752 [EMAIL PROTECTED]
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