Subject: Re: Replacing the sysctl() interface.
To: Jun-ichiro itojun Hagino <email@example.com>
From: Chris G. Demetriou <firstname.lastname@example.org>
Date: 06/05/2000 16:38:18
Jun-ichiro itojun Hagino <email@example.com> writes:
> the issue is that, malloc types are not really module-specific.
really? how many different modules are going to use:
#define M_SEGMENT 43 /* Segment for LFS */
#define M_LFSNODE 44 /* LFS vnode private part */
#define M_FFSNODE 45 /* FFS vnode private part */
#define M_MFSNODE 46 /* MFS vnode private part */
#define M_NQLEASE 47 /* Nqnfs lease */
#define M_NQMHOST 48 /* Nqnfs host address table */
#define M_NFSSVC 50 /* Nfs server structure */
#define M_NFSUID 51 /* Nfs uid mapping structure */
#define M_NFSD 52 /* Nfs server daemon structure */
#define M_ISOFSMNT 57 /* ISOFS mount structure */
#define M_ISOFSNODE 58 /* ISOFS vnode private part */
#define M_MSDOSFSMNT 59 /* MSDOS FS mount structure */
#define M_MSDOSFSFAT 60 /* MSDOS FS fat table */
#define M_MSDOSFSNODE 61 /* MSDOS FS vnode private part */
#define M_MISCFSMNT 64 /* miscfs mount structures */
#define M_MISCFSNODE 65 /* miscfs vnode private part */
#define M_ADOSFSMNT 66 /* adosfs mount structures */
#define M_ADOSFSNODE 67 /* adosfs vnode private part */
#define M_ANODE 68 /* adosfs anode structures and tables. */
#define M_AFS 70 /* Andrew File System */
#define M_ADOSFSBITMAP 71 /* adosfs bitmap */
#define M_NFSRVDESC 72 /* NFS server descriptor */
#define M_NFSDIROFF 73 /* NFS directory cookies */
#define M_NFSBIGFH 74 /* NFS big filehandle */
#define M_EXT2FSNODE 75 /* EXT2FS vnode private part */
#define M_VMSWAP 76 /* VM swap structures */
#define M_VMPAGE 77 /* VM page structures */
#define M_VMPBUCKET 78 /* VM page buckets */
#define M_USB 87 /* USB general */
#define M_USBDEV 88 /* USB device driver */
#define M_POOL 89 /* memory pool structs */
#define M_CODA 90 /* Coda file system structures and tables. */
OK, actually... just start at 43 and go down. few of those will be
used (directly) by multiple modules.
(even M_POOL... only allocation and deallocation of pools will use it!)
> malloc types needs to be unique across the souce code tree to
> diffferentiate between them.
actually, in fact, there's no reason that mutiple modules couldn't use
the same M_FOO name, as long as the values were different, and as long
as the symbols are exposed in the same places. (i.e., if you wanted
to use both in the kernel, they'd have to be static... which is a
lose. but if you wanted to use one in kernel, and one in a loadable
module, and the module were mostly stripped, you'd be fine.)
In the FreeBSD scheme, unless i'm mistaken, the type 'names' etc., are
actually pointers. That gives the necessary amount of uniqueness.
> I believe centralized management in
> sys/sys/malloc.h is good enough.
Look at the list above.
You'll note that 'M_AFS' is there.
The one definition, in itself, is proof that centralized management in
sys/sys/malloc.h is _not_ good enough.