Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753830AbaB0RXv (ORCPT ); Thu, 27 Feb 2014 12:23:51 -0500 Received: from relay3.sgi.com ([192.48.152.1]:58425 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753799AbaB0RXr (ORCPT ); Thu, 27 Feb 2014 12:23:47 -0500 From: Alex Thorlton To: linux-kernel@vger.kernel.org Cc: Alex Thorlton , Gerald Schaefer , Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Andrew Morton , Paolo Bonzini , "Kirill A. Shutemov" , Mel Gorman , Rik van Riel , Ingo Molnar , Peter Zijlstra , Andrea Arcangeli , Oleg Nesterov , "Eric W. Biederman" , Alexander Viro , linux390@de.ibm.com, linux-s390@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org Subject: [PATCH 3/4] mm, thp: Add VM_INIT_DEF_MASK and PRCTL_THP_DISABLE Date: Thu, 27 Feb 2014 11:23:25 -0600 Message-Id: X-Mailer: git-send-email 1.7.12.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds a VM_INIT_DEF_MASK, to allow us to set the default flags for VMs. It also adds a prctl control which alllows us to set the THP disable bit in mm->def_flags so that VMs will pick up the setting as they are created. Signed-off-by: Alex Thorlton Suggested-by: Oleg Nesterov Cc: Gerald Schaefer Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Andrew Morton Cc: Paolo Bonzini Cc: "Kirill A. Shutemov" Cc: Mel Gorman Cc: Rik van Riel Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Andrea Arcangeli Cc: Oleg Nesterov Cc: "Eric W. Biederman" Cc: Alexander Viro Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-api@vger.kernel.org --- include/linux/mm.h | 3 +++ include/uapi/linux/prctl.h | 3 +++ kernel/fork.c | 11 ++++++++--- kernel/sys.c | 15 +++++++++++++++ 4 files changed, 29 insertions(+), 3 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index f28f46e..0314e4c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -177,6 +177,9 @@ extern unsigned int kobjsize(const void *objp); */ #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP) +/* This mask defines which mm->def_flags a process can inherit its parent */ +#define VM_INIT_DEF_MASK VM_NOHUGEPAGE + /* * mapping from the currently active vm_flags protection bits (the * low four bits) to a page protection mask.. diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 289760f..58afc04 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -149,4 +149,7 @@ #define PR_GET_TID_ADDRESS 40 +#define PR_SET_THP_DISABLE 41 +#define PR_GET_THP_DISABLE 42 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/fork.c b/kernel/fork.c index a17621c..9fc0a30 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -529,8 +529,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p) atomic_set(&mm->mm_count, 1); init_rwsem(&mm->mmap_sem); INIT_LIST_HEAD(&mm->mmlist); - mm->flags = (current->mm) ? - (current->mm->flags & MMF_INIT_MASK) : default_dump_filter; mm->core_state = NULL; atomic_long_set(&mm->nr_ptes, 0); memset(&mm->rss_stat, 0, sizeof(mm->rss_stat)); @@ -539,8 +537,15 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p) mm_init_owner(mm, p); clear_tlb_flush_pending(mm); - if (likely(!mm_alloc_pgd(mm))) { + if (current->mm) { + mm->flags = current->mm->flags & MMF_INIT_MASK; + mm->def_flags = current->mm->def_flags & VM_INIT_DEF_MASK; + } else { + mm->flags = default_dump_filter; mm->def_flags = 0; + } + + if (likely(!mm_alloc_pgd(mm))) { mmu_notifier_mm_init(mm); return mm; } diff --git a/kernel/sys.c b/kernel/sys.c index c0a58be..aa8d3a0 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1996,6 +1996,21 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, if (arg2 || arg3 || arg4 || arg5) return -EINVAL; return current->no_new_privs ? 1 : 0; + case PR_GET_THP_DISABLE: + if (arg2 || arg3 || arg4 || arg5) + return -EINVAL; + error = !!(me->mm->def_flags & VM_NOHUGEPAGE); + break; + case PR_SET_THP_DISABLE: + if (arg3 || arg4 || arg5) + return -EINVAL; + down_write(&me->mm->mmap_sem); + if (arg2) + me->mm->def_flags |= VM_NOHUGEPAGE; + else + me->mm->def_flags &= ~VM_NOHUGEPAGE; + up_write(&me->mm->mmap_sem); + break; default: error = -EINVAL; break; -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/