From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f200.google.com (mail-qt0-f200.google.com [209.85.216.200]) by kanga.kvack.org (Postfix) with ESMTP id 482FD6B03A1 for ; Mon, 17 Jul 2017 18:28:55 -0400 (EDT) Received: by mail-qt0-f200.google.com with SMTP id o8so1723372qtc.1 for ; Mon, 17 Jul 2017 15:28:55 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id p35si384829qtd.279.2017.07.17.15.28.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 17 Jul 2017 15:28:54 -0700 (PDT) From: Mike Kravetz Subject: [RFC PATCH 1/3] mm:hugetlb: Define system call hugetlb size encodings in single file Date: Mon, 17 Jul 2017 15:27:59 -0700 Message-Id: <1500330481-28476-2-git-send-email-mike.kravetz@oracle.com> In-Reply-To: <1500330481-28476-1-git-send-email-mike.kravetz@oracle.com> References: <20170328175408.GD7838@bombadil.infradead.org> <1500330481-28476-1-git-send-email-mike.kravetz@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Matthew Wilcox , akpm@linux-foundation.org, mhocko@suse.com, ak@linux.intel.com, mtk.manpages@gmail.com, Davidlohr Bueso , khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, aarcange@redhat.com, Mike Kravetz If hugetlb pages are requested in mmap or shmget system calls, a huge page size other than default can be requested. This is accomplished by encoding the log2 of the huge page size in the upper bits of the flag argument. asm-generic and arch specific headers all define the same values for these encodings. Put common definitions in a single header file. arch specific code can still override if desired. Signed-off-by: Mike Kravetz --- include/uapi/asm-generic/hugetlb_encode.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 include/uapi/asm-generic/hugetlb_encode.h diff --git a/include/uapi/asm-generic/hugetlb_encode.h b/include/uapi/asm-generic/hugetlb_encode.h new file mode 100644 index 0000000..aa09fc0 --- /dev/null +++ b/include/uapi/asm-generic/hugetlb_encode.h @@ -0,0 +1,30 @@ +#ifndef _ASM_GENERIC_HUGETLB_ENCODE_H_ +#define _ASM_GENERIC_HUGETLB_ENCODE_H_ + +/* + * Several system calls take a flag to request "hugetlb" huge pages. + * Without further specification, these system calls will use the + * system's default huge page size. If a system supports multiple + * huge page sizes, the desired huge page size can be specified in + * bits [26:31] of the flag arguments. The value in these 6 bits + * will encode the log2 of the huge page size. + * + * The following definitions are associated with this huge page size + * encoding in flag arguments. System call specific header files + * that use this encoding should include this file. They can then + * provide definitions based on these with their own specific prefix. + * for example #define MAP_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT. + */ + +#define HUGETLB_FLAG_ENCODE_SHIFT 26 +#define HUGETLB_FLAG_ENCODE_MASK 0x3f + +#define HUGETLB_FLAG_ENCODE_512KB (19 << MAP_HUGE_SHIFT +#define HUGETLB_FLAG_ENCODE_1MB (20 << MAP_HUGE_SHIFT) +#define HUGETLB_FLAG_ENCODE_2MB (21 << MAP_HUGE_SHIFT) +#define HUGETLB_FLAG_ENCODE_8MB (23 << MAP_HUGE_SHIFT) +#define HUGETLB_FLAG_ENCODE_16MB (24 << MAP_HUGE_SHIFT) +#define HUGETLB_FLAG_ENCODE_1GB (30 << MAP_HUGE_SHIFT) +#define HUGETLB_FLAG_ENCODE__16GB (34 << MAP_HUGE_SHIFT) + +#endif /* _ASM_GENERIC_HUGETLB_ENCODE_H_ */ -- 2.7.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org