Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760479AbcLPJq4 (ORCPT ); Fri, 16 Dec 2016 04:46:56 -0500 Received: from aserp1050.oracle.com ([141.146.126.70]:31909 "EHLO aserp1050.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760414AbcLPJqk (ORCPT ); Fri, 16 Dec 2016 04:46:40 -0500 From: Vegard Nossum To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Rik van Riel , Matthew Wilcox , Peter Zijlstra , Andrew Morton , Michal Hocko , Al Viro , Ingo Molnar , Linus Torvalds , Vegard Nossum Subject: [PATCH 2/4] mm: add new mmget() helper Date: Fri, 16 Dec 2016 09:22:00 +0100 Message-Id: <20161216082202.21044-2-vegard.nossum@oracle.com> X-Mailer: git-send-email 2.11.0.1.gaa10c3f In-Reply-To: <20161216082202.21044-1-vegard.nossum@oracle.com> References: <20161216082202.21044-1-vegard.nossum@oracle.com> X-Source-IP: aserp1040.oracle.com [141.146.126.69] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6141 Lines: 198 Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_users' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_users);/mmget\(\1\);/' git grep -l 'atomic_inc.*mm_users' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_users);/mmget\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. Cc: Andrew Morton Cc: Michal Hocko Signed-off-by: Vegard Nossum --- arch/arc/kernel/smp.c | 2 +- arch/blackfin/mach-common/smp.c | 2 +- arch/frv/mm/mmu-context.c | 2 +- arch/metag/kernel/smp.c | 2 +- arch/sh/kernel/smp.c | 2 +- arch/xtensa/kernel/smp.c | 2 +- include/linux/sched.h | 5 +++++ kernel/fork.c | 4 ++-- mm/swapfile.c | 10 +++++----- virt/kvm/async_pf.c | 2 +- 10 files changed, 19 insertions(+), 14 deletions(-) diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c index 9cbc7aba3ede..eec70cb71db1 100644 --- a/arch/arc/kernel/smp.c +++ b/arch/arc/kernel/smp.c @@ -124,7 +124,7 @@ void start_kernel_secondary(void) /* MMU, Caches, Vector Table, Interrupts etc */ setup_processor(); - atomic_inc(&mm->mm_users); + mmget(mm); mmgrab(mm); current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c index bc5617ef7128..a2e6db2ce811 100644 --- a/arch/blackfin/mach-common/smp.c +++ b/arch/blackfin/mach-common/smp.c @@ -307,7 +307,7 @@ void secondary_start_kernel(void) local_irq_disable(); /* Attach the new idle task to the global mm. */ - atomic_inc(&mm->mm_users); + mmget(mm); mmgrab(mm); current->active_mm = mm; diff --git a/arch/frv/mm/mmu-context.c b/arch/frv/mm/mmu-context.c index 81757d55a5b5..3473bde77f56 100644 --- a/arch/frv/mm/mmu-context.c +++ b/arch/frv/mm/mmu-context.c @@ -188,7 +188,7 @@ int cxn_pin_by_pid(pid_t pid) task_lock(tsk); if (tsk->mm) { mm = tsk->mm; - atomic_inc(&mm->mm_users); + mmget(mm); ret = 0; } task_unlock(tsk); diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c index af9cff547a19..c622293254e4 100644 --- a/arch/metag/kernel/smp.c +++ b/arch/metag/kernel/smp.c @@ -344,7 +344,7 @@ asmlinkage void secondary_start_kernel(void) * All kernel threads share the same mm context; grab a * reference and switch to it. */ - atomic_inc(&mm->mm_users); + mmget(mm); mmgrab(mm); current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index ee379c699c08..edc4769b047e 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -179,7 +179,7 @@ asmlinkage void start_secondary(void) enable_mmu(); mmgrab(mm); - atomic_inc(&mm->mm_users); + mmget(mm); current->active_mm = mm; #ifdef CONFIG_MMU enter_lazy_tlb(mm, current); diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c index 9bf5cea3bae4..fcea72019df7 100644 --- a/arch/xtensa/kernel/smp.c +++ b/arch/xtensa/kernel/smp.c @@ -135,7 +135,7 @@ void secondary_start_kernel(void) /* All kernel threads share the same mm context. */ - atomic_inc(&mm->mm_users); + mmget(mm); mmgrab(mm); current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); diff --git a/include/linux/sched.h b/include/linux/sched.h index 31ae1f49eebb..2ca3e15dad3b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2899,6 +2899,11 @@ static inline void mmdrop_async(struct mm_struct *mm) } } +static inline void mmget(struct mm_struct *mm) +{ + atomic_inc(&mm->mm_users); +} + static inline bool mmget_not_zero(struct mm_struct *mm) { return atomic_inc_not_zero(&mm->mm_users); diff --git a/kernel/fork.c b/kernel/fork.c index 997ac1d584f7..f9c32dc6ccbc 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -989,7 +989,7 @@ struct mm_struct *get_task_mm(struct task_struct *task) if (task->flags & PF_KTHREAD) mm = NULL; else - atomic_inc(&mm->mm_users); + mmget(mm); } task_unlock(task); return mm; @@ -1177,7 +1177,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk) vmacache_flush(tsk); if (clone_flags & CLONE_VM) { - atomic_inc(&oldmm->mm_users); + mmget(oldmm); mm = oldmm; goto good_mm; } diff --git a/mm/swapfile.c b/mm/swapfile.c index f30438970cd1..cf73169ce153 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1402,7 +1402,7 @@ int try_to_unuse(unsigned int type, bool frontswap, * that. */ start_mm = &init_mm; - atomic_inc(&init_mm.mm_users); + mmget(&init_mm); /* * Keep on scanning until all entries have gone. Usually, @@ -1451,7 +1451,7 @@ int try_to_unuse(unsigned int type, bool frontswap, if (atomic_read(&start_mm->mm_users) == 1) { mmput(start_mm); start_mm = &init_mm; - atomic_inc(&init_mm.mm_users); + mmget(&init_mm); } /* @@ -1488,8 +1488,8 @@ int try_to_unuse(unsigned int type, bool frontswap, struct mm_struct *prev_mm = start_mm; struct mm_struct *mm; - atomic_inc(&new_start_mm->mm_users); - atomic_inc(&prev_mm->mm_users); + mmget(new_start_mm); + mmget(prev_mm); spin_lock(&mmlist_lock); while (swap_count(*swap_map) && !retval && (p = p->next) != &start_mm->mmlist) { @@ -1512,7 +1512,7 @@ int try_to_unuse(unsigned int type, bool frontswap, if (set_start_mm && *swap_map < swcount) { mmput(new_start_mm); - atomic_inc(&mm->mm_users); + mmget(mm); new_start_mm = mm; set_start_mm = 0; } diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index efeceb0a222d..9ec9cef2b207 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -200,7 +200,7 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, unsigned long hva, work->addr = hva; work->arch = *arch; work->mm = current->mm; - atomic_inc(&work->mm->mm_users); + mmget(work->mm); kvm_get_kvm(work->vcpu->kvm); /* this can't really happen otherwise gfn_to_pfn_async -- 2.11.0.1.gaa10c3f