Commit 4da243ac authored by Mike Kravetz's avatar Mike Kravetz Committed by Linus Torvalds
Browse files

mm: shm: use new hugetlb size encoding definitions 

Use the common definitions from hugetlb_encode.h header file for
encoding hugetlb size definitions in shmget system call flags.

In addition, move these definitions from the internal (kernel) to user
(uapi) header file.

Link: http://lkml.kernel.org/r/1501527386-10736-4-git-send-email-mike.kravetz@oracle.com


Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Suggested-by: default avatarMatthew Wilcox <willy@infradead.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent aafd4562

include/linux/shm.h

+0 −17
Original line number Diff line number Diff line
@@ -27,23 +27,6 @@ struct shmid_kernel /* private to the kernel */ 
/* shm_mode upper byte flags */

#define	SHM_DEST	01000	/* segment will be destroyed on last detach */

#define SHM_LOCKED      02000   /* segment will not be swapped */

#define SHM_HUGETLB     04000   /* segment will use huge TLB pages */

#define SHM_NORESERVE   010000  /* don't check for reservations */



/* Bits [26:31] are reserved */



/*

 * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.

 * This gives us 6 bits, which is enough until someone invents 128 bit address

 * spaces.

 *

 * Assume these are all power of twos.

 * When 0 use the default page size.

 */

#define SHM_HUGE_SHIFT  26

#define SHM_HUGE_MASK   0x3f

#define SHM_HUGE_2MB    (21 << SHM_HUGE_SHIFT)

#define SHM_HUGE_1GB    (30 << SHM_HUGE_SHIFT)



#ifdef CONFIG_SYSVIPC

struct sysv_shm {

include/uapi/linux/shm.h

+29 −2
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 


#include <linux/ipc.h>

#include <linux/errno.h>

#include <asm-generic/hugetlb_encode.h>

#ifndef __KERNEL__

#include <unistd.h>

#endif
@@ -40,11 +41,37 @@ struct shmid_ds { 
/* Include the definition of shmid64_ds and shminfo64 */

#include <asm/shmbuf.h>



/* permission flag for shmget */

/*

 * shmget() shmflg values.

 */

/* The bottom nine bits are the same as open(2) mode flags */

#define SHM_R		0400	/* or S_IRUGO from <linux/stat.h> */

#define SHM_W		0200	/* or S_IWUGO from <linux/stat.h> */

/* Bits 9 & 10 are IPC_CREAT and IPC_EXCL */

#define SHM_HUGETLB	04000	/* segment will use huge TLB pages */

#define SHM_NORESERVE	010000	/* don't check for reservations */



/*

 * Huge page size encoding when SHM_HUGETLB is specified, and a huge page

 * size other than the default is desired.  See hugetlb_encode.h

 */

#define SHM_HUGE_SHIFT	HUGETLB_FLAG_ENCODE_SHIFT

#define SHM_HUGE_MASK	HUGETLB_FLAG_ENCODE_MASK



#define SHM_HUGE_64KB	HUGETLB_FLAG_ENCODE_64KB

#define SHM_HUGE_512KB	HUGETLB_FLAG_ENCODE_512KB

#define SHM_HUGE_1MB	HUGETLB_FLAG_ENCODE_1MB

#define SHM_HUGE_2MB	HUGETLB_FLAG_ENCODE_2MB

#define SHM_HUGE_8MB	HUGETLB_FLAG_ENCODE_8MB

#define SHM_HUGE_16MB	HUGETLB_FLAG_ENCODE_16MB

#define SHM_HUGE_256MB	HUGETLB_FLAG_ENCODE_256MB

#define SHM_HUGE_1GB	HUGETLB_FLAG_ENCODE_1GB

#define SHM_HUGE_2GB	HUGETLB_FLAG_ENCODE_2GB

#define SHM_HUGE_16GB	HUGETLB_FLAG_ENCODE_16GB



/* mode for attach */

/*

 * shmat() shmflg values

 */

#define	SHM_RDONLY	010000	/* read-only access */

#define	SHM_RND		020000	/* round attach address to SHMLBA boundary */

#define	SHM_REMAP	040000	/* take-over region on attach */

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