From patchwork Tue Jun 2 18:13:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric B Munson X-Patchwork-Id: 6530521 Return-Path: X-Original-To: patchwork-linux-parisc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 9C141C0020 for ; Tue, 2 Jun 2015 18:13:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 540A8204B5 for ; Tue, 2 Jun 2015 18:13:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F7AA20522 for ; Tue, 2 Jun 2015 18:13:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759351AbbFBSNu (ORCPT ); Tue, 2 Jun 2015 14:13:50 -0400 Received: from prod-mail-xrelay07.akamai.com ([72.246.2.115]:33785 "EHLO prod-mail-xrelay07.akamai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759283AbbFBSN3 (ORCPT ); Tue, 2 Jun 2015 14:13:29 -0400 Received: from prod-mail-xrelay07.akamai.com (localhost.localdomain [127.0.0.1]) by postfix.imss70 (Postfix) with ESMTP id A78E0485EA; Tue, 2 Jun 2015 18:13:27 +0000 (GMT) Received: from prod-mail-relay06.akamai.com (prod-mail-relay06.akamai.com [172.17.120.126]) by prod-mail-xrelay07.akamai.com (Postfix) with ESMTP id 9B5044862B; Tue, 2 Jun 2015 18:13:27 +0000 (GMT) Received: from bos-lp6ds.kendall.corp.akamai.com (bos-lp6ds.kendall.corp.akamai.com [172.28.12.164]) by prod-mail-relay06.akamai.com (Postfix) with ESMTP id 8C3022030; Tue, 2 Jun 2015 18:13:27 +0000 (GMT) From: Eric B Munson To: Andrew Morton Cc: Eric B Munson , Michal Hocko , Michael Kerrisk , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH V2 1/3] Add mmap flag to request pages are locked after page fault Date: Tue, 2 Jun 2015 14:13:24 -0400 Message-Id: <1433268806-17109-2-git-send-email-emunson@akamai.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1433268806-17109-1-git-send-email-emunson@akamai.com> References: <1433268806-17109-1-git-send-email-emunson@akamai.com> Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The cost of faulting in all memory to be locked can be very high when working with large mappings. If only portions of the mapping will be used this can incur a high penalty for locking. For the example of a large file, this is the usage pattern for a large statical language model (probably applies to other statical or graphical models as well). For the security example, any application transacting in data that cannot be swapped out (credit card data, medical records, etc). This patch introduces the ability to request that pages are not pre-faulted, but are placed on the unevictable LRU when they are finally faulted in. To keep accounting checks out of the page fault path, users are billed for the entire mapping lock as if MAP_LOCKED was used. Signed-off-by: Eric B Munson Cc: Michal Hocko Cc: Michael Kerrisk Cc: linux-alpha@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-mm@kvack.org Cc: linux-arch@vger.kernel.org Cc: linux-api@vger.kernel.org --- arch/alpha/include/uapi/asm/mman.h | 1 + arch/mips/include/uapi/asm/mman.h | 1 + arch/parisc/include/uapi/asm/mman.h | 1 + arch/powerpc/include/uapi/asm/mman.h | 1 + arch/sparc/include/uapi/asm/mman.h | 1 + arch/tile/include/uapi/asm/mman.h | 1 + arch/xtensa/include/uapi/asm/mman.h | 1 + include/linux/mm.h | 1 + include/linux/mman.h | 3 ++- include/uapi/asm-generic/mman.h | 1 + mm/mmap.c | 4 ++-- mm/swap.c | 3 ++- 12 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h index 0086b47..15e96e1 100644 --- a/arch/alpha/include/uapi/asm/mman.h +++ b/arch/alpha/include/uapi/asm/mman.h @@ -30,6 +30,7 @@ #define MAP_NONBLOCK 0x40000 /* do not block on IO */ #define MAP_STACK 0x80000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x100000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x200000 /* Lock pages after they are faulted in, do not prefault */ #define MS_ASYNC 1 /* sync memory asynchronously */ #define MS_SYNC 2 /* synchronous memory sync */ diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h index cfcb876..47846a5 100644 --- a/arch/mips/include/uapi/asm/mman.h +++ b/arch/mips/include/uapi/asm/mman.h @@ -48,6 +48,7 @@ #define MAP_NONBLOCK 0x20000 /* do not block on IO */ #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x100000 /* Lock pages after they are faulted in, do not prefault */ /* * Flags for msync diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h index 294d251..1514cd7 100644 --- a/arch/parisc/include/uapi/asm/mman.h +++ b/arch/parisc/include/uapi/asm/mman.h @@ -24,6 +24,7 @@ #define MAP_NONBLOCK 0x20000 /* do not block on IO */ #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x100000 /* Lock pages after they are faulted in, do not prefault */ #define MS_SYNC 1 /* synchronous memory sync */ #define MS_ASYNC 2 /* sync memory asynchronously */ diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h index 6ea26df..fce74fe 100644 --- a/arch/powerpc/include/uapi/asm/mman.h +++ b/arch/powerpc/include/uapi/asm/mman.h @@ -27,5 +27,6 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x80000 /* Lock pages after they are faulted in, do not prefault */ #endif /* _UAPI_ASM_POWERPC_MMAN_H */ diff --git a/arch/sparc/include/uapi/asm/mman.h b/arch/sparc/include/uapi/asm/mman.h index 0b14df3..12425d8 100644 --- a/arch/sparc/include/uapi/asm/mman.h +++ b/arch/sparc/include/uapi/asm/mman.h @@ -22,6 +22,7 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x80000 /* Lock pages after they are faulted in, do not prefault */ #endif /* _UAPI__SPARC_MMAN_H__ */ diff --git a/arch/tile/include/uapi/asm/mman.h b/arch/tile/include/uapi/asm/mman.h index 81b8fc3..ec04eaf 100644 --- a/arch/tile/include/uapi/asm/mman.h +++ b/arch/tile/include/uapi/asm/mman.h @@ -29,6 +29,7 @@ #define MAP_DENYWRITE 0x0800 /* ETXTBSY */ #define MAP_EXECUTABLE 0x1000 /* mark it as an executable */ #define MAP_HUGETLB 0x4000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x8000 /* Lock pages after they are faulted in, do not prefault */ /* diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h index 201aec0..42d43cc 100644 --- a/arch/xtensa/include/uapi/asm/mman.h +++ b/arch/xtensa/include/uapi/asm/mman.h @@ -55,6 +55,7 @@ #define MAP_NONBLOCK 0x20000 /* do not block on IO */ #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x100000 /* Lock pages after they are faulted in, do not prefault */ #ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED # define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be * uninitialized */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 0755b9f..3e31457 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -126,6 +126,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */ +#define VM_LOCKONFAULT 0x00001000 /* Lock the pages covered when they are faulted in */ #define VM_LOCKED 0x00002000 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */ diff --git a/include/linux/mman.h b/include/linux/mman.h index 16373c8..437264b 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -86,7 +86,8 @@ calc_vm_flag_bits(unsigned long flags) { return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | - _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ); + _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | + _calc_vm_trans(flags, MAP_LOCKONFAULT,VM_LOCKONFAULT); } unsigned long vm_commit_limit(void); diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h index e9fe6fd..fc4e586 100644 --- a/include/uapi/asm-generic/mman.h +++ b/include/uapi/asm-generic/mman.h @@ -12,6 +12,7 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ +#define MAP_LOCKONFAULT 0x80000 /* Lock pages after they are faulted in, do not prefault */ /* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */ diff --git a/mm/mmap.c b/mm/mmap.c index bb50cac..ba1a6bf 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1233,7 +1233,7 @@ static inline int mlock_future_check(struct mm_struct *mm, unsigned long locked, lock_limit; /* mlock MCL_FUTURE? */ - if (flags & VM_LOCKED) { + if (flags & (VM_LOCKED | VM_LOCKONFAULT)) { locked = len >> PAGE_SHIFT; locked += mm->locked_vm; lock_limit = rlimit(RLIMIT_MEMLOCK); @@ -1301,7 +1301,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; - if (flags & MAP_LOCKED) + if (flags & (MAP_LOCKED | MAP_LOCKONFAULT)) if (!can_do_mlock()) return -EPERM; diff --git a/mm/swap.c b/mm/swap.c index a7251a8..07c905e 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -711,7 +711,8 @@ void lru_cache_add_active_or_unevictable(struct page *page, { VM_BUG_ON_PAGE(PageLRU(page), page); - if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) { + if (likely((vma->vm_flags & (VM_LOCKED | VM_LOCKONFAULT)) == 0) || + (vma->vm_flags & VM_SPECIAL)) { SetPageActive(page); lru_cache_add(page); return;