From 4e15a073a168b62311db911a55c4d4f1500c2821 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 26 Oct 2018 15:03:39 -0700 Subject: [PATCH] Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" Revert 5ff7091f5a2ca ("mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"). MMU_INVALIDATE_DOES_NOT_BLOCK flags was the only one used and it is no longer needed since 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers"). We now have a full support for per range !blocking behavior so we can drop the stop gap workaround which the per notifier flag was used for. Link: http://lkml.kernel.org/r/20180827112623.8992-4-mhocko@kernel.org Signed-off-by: Michal Hocko Cc: David Rientjes Cc: Boris Ostrovsky Cc: Jerome Glisse Cc: Juergen Gross Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/infiniband/hw/hfi1/mmu_rb.c | 1 - drivers/iommu/amd_iommu_v2.c | 1 - drivers/iommu/intel-svm.c | 1 - drivers/misc/sgi-gru/grutlbpurge.c | 1 - include/linux/mmu_notifier.h | 23 --------------------- mm/mmu_notifier.c | 31 ----------------------------- virt/kvm/kvm_main.c | 1 - 7 files changed, 59 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c index e1c7996c018e..475b769e120c 100644 --- a/drivers/infiniband/hw/hfi1/mmu_rb.c +++ b/drivers/infiniband/hw/hfi1/mmu_rb.c @@ -77,7 +77,6 @@ static void do_remove(struct mmu_rb_handler *handler, static void handle_remove(struct work_struct *work); static const struct mmu_notifier_ops mn_opts = { - .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .invalidate_range_start = mmu_notifier_range_start, }; diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index 58da65df03f5..fd552235bd13 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -427,7 +427,6 @@ static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm) } static const struct mmu_notifier_ops iommu_mn = { - .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .release = mn_release, .clear_flush_young = mn_clear_flush_young, .invalidate_range = mn_invalidate_range, diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 4a03e5090952..db301efe126d 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -273,7 +273,6 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) } static const struct mmu_notifier_ops intel_mmuops = { - .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .release = intel_mm_release, .change_pte = intel_change_pte, .invalidate_range = intel_invalidate_range, diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c index be28f05bfafa..03b49d52092e 100644 --- a/drivers/misc/sgi-gru/grutlbpurge.c +++ b/drivers/misc/sgi-gru/grutlbpurge.c @@ -261,7 +261,6 @@ static void gru_release(struct mmu_notifier *mn, struct mm_struct *mm) static const struct mmu_notifier_ops gru_mmuops = { - .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .invalidate_range_start = gru_invalidate_range_start, .invalidate_range_end = gru_invalidate_range_end, .release = gru_release, diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 698e371aafe3..9893a6432adf 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -2,7 +2,6 @@ #ifndef _LINUX_MMU_NOTIFIER_H #define _LINUX_MMU_NOTIFIER_H -#include #include #include #include @@ -11,9 +10,6 @@ struct mmu_notifier; struct mmu_notifier_ops; -/* mmu_notifier_ops flags */ -#define MMU_INVALIDATE_DOES_NOT_BLOCK (0x01) - #ifdef CONFIG_MMU_NOTIFIER /* @@ -30,15 +26,6 @@ struct mmu_notifier_mm { }; struct mmu_notifier_ops { - /* - * Flags to specify behavior of callbacks for this MMU notifier. - * Used to determine which context an operation may be called. - * - * MMU_INVALIDATE_DOES_NOT_BLOCK: invalidate_range_* callbacks do not - * block - */ - int flags; - /* * Called either by mmu_notifier_unregister or when the mm is * being destroyed by exit_mmap, always before all pages are @@ -183,10 +170,6 @@ struct mmu_notifier_ops { * Note that this function might be called with just a sub-range * of what was passed to invalidate_range_start()/end(), if * called between those functions. - * - * If this callback cannot block, and invalidate_range_{start,end} - * cannot block, mmu_notifier_ops.flags should have - * MMU_INVALIDATE_DOES_NOT_BLOCK set. */ void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end); @@ -241,7 +224,6 @@ extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, bool only_end); extern void __mmu_notifier_invalidate_range(struct mm_struct *mm, unsigned long start, unsigned long end); -extern bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm); static inline void mmu_notifier_release(struct mm_struct *mm) { @@ -495,11 +477,6 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, { } -static inline bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm) -{ - return false; -} - static inline void mmu_notifier_mm_init(struct mm_struct *mm) { } diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 82bb1a939c0e..5119ff846769 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -247,37 +247,6 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm, } EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range); -/* - * Must be called while holding mm->mmap_sem for either read or write. - * The result is guaranteed to be valid until mm->mmap_sem is dropped. - */ -bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm) -{ - struct mmu_notifier *mn; - int id; - bool ret = false; - - WARN_ON_ONCE(!rwsem_is_locked(&mm->mmap_sem)); - - if (!mm_has_notifiers(mm)) - return ret; - - id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { - if (!mn->ops->invalidate_range && - !mn->ops->invalidate_range_start && - !mn->ops->invalidate_range_end) - continue; - - if (!(mn->ops->flags & MMU_INVALIDATE_DOES_NOT_BLOCK)) { - ret = true; - break; - } - } - srcu_read_unlock(&srcu, id); - return ret; -} - static int do_mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm, int take_mmap_sem) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 786ade1843a2..2679e476b6c3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -497,7 +497,6 @@ static void kvm_mmu_notifier_release(struct mmu_notifier *mn, } static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { - .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start, .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end, .clear_flush_young = kvm_mmu_notifier_clear_flush_young, -- 2.34.1