[newlib 28/65] Include the psind in data returned by mincore(2).

Sebastian Huber sebastian.huber at embedded-brains.de
Thu Jul 7 11:58:35 UTC 2022

From: Mark Johnston <markj at FreeBSD.org>

Currently we use a single bit to indicate whether the virtual page is
part of a superpage.  To support a forthcoming implementation of
non-transparent 1GB superpages, it is useful to provide more detailed
information about large page sizes.

The change converts MINCORE_SUPER into a mask for MINCORE_PSIND(psind)
values, indicating a mapping of size psind, where psind is an index into
the pagesizes array returned by getpagesizes(3), which in turn comes
from the hw.pagesizes sysctl.  MINCORE_PSIND(1) is equal to the old

For now, two bits are used to record the page size, permitting values
of MAXPAGESIZES up to 4.

Reviewed by:	alc, kib
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D26238
 newlib/libc/sys/rtems/include/sys/mman.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/newlib/libc/sys/rtems/include/sys/mman.h b/newlib/libc/sys/rtems/include/sys/mman.h
index 99c1eb8b3..6d861422d 100644
--- a/newlib/libc/sys/rtems/include/sys/mman.h
+++ b/newlib/libc/sys/rtems/include/sys/mman.h
@@ -179,7 +179,8 @@
 #define	MINCORE_MODIFIED	 0x4 /* Page has been modified by us */
 #define	MINCORE_REFERENCED_OTHER 0x8 /* Page has been referenced */
 #define	MINCORE_MODIFIED_OTHER	0x10 /* Page has been modified */
-#define	MINCORE_SUPER		0x20 /* Page is a "super" page */
+#define	MINCORE_SUPER		0x60 /* Page is a "super" page */
+#define	MINCORE_PSIND(i)	(((i) << 5) & MINCORE_SUPER) /* Page size */
  * Anonymous object constant for shm_open().

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