Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751573AbdGZJxn (ORCPT ); Wed, 26 Jul 2017 05:53:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:43064 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750908AbdGZJxm (ORCPT ); Wed, 26 Jul 2017 05:53:42 -0400 Date: Wed, 26 Jul 2017 11:53:38 +0200 From: Michal Hocko To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Matthew Wilcox , akpm@linux-foundation.org, ak@linux.intel.com, mtk.manpages@gmail.com, Davidlohr Bueso , khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, aarcange@redhat.com Subject: Re: [RFC PATCH 3/3] mm: shm: Use new hugetlb size encoding definitions Message-ID: <20170726095338.GF2981@dhcp22.suse.cz> References: <20170328175408.GD7838@bombadil.infradead.org> <1500330481-28476-1-git-send-email-mike.kravetz@oracle.com> <1500330481-28476-4-git-send-email-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1500330481-28476-4-git-send-email-mike.kravetz@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3553 Lines: 99 On Mon 17-07-17 15:28:01, Mike Kravetz wrote: > 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 to the from the internal to user > (uapi) header file. s@to the from@from@ > > Suggested-by: Matthew Wilcox > Signed-off-by: Mike Kravetz with s@HUGETLB_FLAG_ENCODE__16GB@HUGETLB_FLAG_ENCODE_16GB@ Acked-by: Michal Hocko > --- > include/linux/shm.h | 17 ----------------- > include/uapi/linux/shm.h | 23 +++++++++++++++++++++-- > 2 files changed, 21 insertions(+), 19 deletions(-) > > diff --git a/include/linux/shm.h b/include/linux/shm.h > index 04e8818..d56285a 100644 > --- a/include/linux/shm.h > +++ b/include/linux/shm.h > @@ -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 { > diff --git a/include/uapi/linux/shm.h b/include/uapi/linux/shm.h > index 1fbf24e..329bc17 100644 > --- a/include/uapi/linux/shm.h > +++ b/include/uapi/linux/shm.h > @@ -3,6 +3,7 @@ > > #include > #include > +#include > #ifndef __KERNEL__ > #include > #endif > @@ -40,11 +41,29 @@ struct shmid_ds { > /* Include the definition of shmid64_ds and shminfo64 */ > #include > > -/* 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 */ > #define SHM_W 0200 /* or S_IWUGO from */ > +/* 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 */ > > -/* mode for attach */ > +/* > + * 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 MAP_HUGE_512KB HUGETLB_FLAG_ENCODE_512KB > +#define MAP_HUGE_1MB HUGETLB_FLAG_ENCODE_1MB > +#define MAP_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB > +#define MAP_HUGE_8MB HUGETLB_FLAG_ENCODE_8MB > +#define MAP_HUGE_16MB HUGETLB_FLAG_ENCODE_16MB > +#define MAP_HUGE_1GB HUGETLB_FLAG_ENCODE_1GB > +#define MAP_HUGE_16GB HUGETLB_FLAG_ENCODE__16GB > + > +/* 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 */ > -- > 2.7.5 > -- Michal Hocko SUSE Labs