Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"

Revert 7b3a0e3e2cef1 ("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 f4db9358e5c1 ("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 <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c
index e1c7996c018efe688dbe081cc0928f05c5f0bbdd..475b769e120ca3bb7ba6db662c5815cd1575a905 100644 (file)
--- 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 58da65df03f5e2551352c9d99c42a794d036b8e5..fd552235bd13196591689f8f21fd0a37a7d834e9 100644 (file)
--- 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 4a03e50909520e5eb40d6245fa3e1affda769780..db301efe126d4ac9cf2aeb606489565135db7e7d 100644 (file)
--- 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 be28f05bfafa9ee41a53c642f0e384812ea88adf..03b49d52092ef6b4c795a63a93b55871046d129b 100644 (file)
--- 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 698e371aafe327d71904c2a2872bf1da83fb74f9..9893a6432adf9064c585b500f47754ce7909daed 100644 (file)
--- 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 <linux/types.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/mm_types.h>
@@ -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 82bb1a939c0e496affc2849c1e1af795fe3d5d96..5119ff8467690f6696c63489e96062ece67c24fa 100644 (file)
--- 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 786ade1843a2b69e3567538587388df4ce854c9d..2679e476b6c3970f5e6479c89183a564639db257 100644 (file)
--- 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,