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authorMichel Lespinasse <michel@lespinasse.org>2023-02-27 09:36:09 -0800
committerAndrew Morton <akpm@linux-foundation.org>2023-04-05 20:02:57 -0700
commit20cce633f4254cc0df39665449726e3172518f6c (patch)
tree7988880c4a5fa5b34ffe26a7f6a9ea6af56e434d /kernel
parent0b6cc04f3db3604c1485049bc9582523c2b44b75 (diff)
mm: rcu safe VMA freeing
This prepares for page faults handling under VMA lock, looking up VMAs under protection of an rcu read lock, instead of the usual mmap read lock. Link: https://lkml.kernel.org/r/20230227173632.3292573-11-surenb@google.com Signed-off-by: Michel Lespinasse <michel@lespinasse.org> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index cea99f003f24..93ec6e14bb65 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -479,12 +479,30 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
return new;
}
-void vm_area_free(struct vm_area_struct *vma)
+static void __vm_area_free(struct vm_area_struct *vma)
{
free_anon_vma_name(vma);
kmem_cache_free(vm_area_cachep, vma);
}
+#ifdef CONFIG_PER_VMA_LOCK
+static void vm_area_free_rcu_cb(struct rcu_head *head)
+{
+ struct vm_area_struct *vma = container_of(head, struct vm_area_struct,
+ vm_rcu);
+ __vm_area_free(vma);
+}
+#endif
+
+void vm_area_free(struct vm_area_struct *vma)
+{
+#ifdef CONFIG_PER_VMA_LOCK
+ call_rcu(&vma->vm_rcu, vm_area_free_rcu_cb);
+#else
+ __vm_area_free(vma);
+#endif
+}
+
static void account_kernel_stack(struct task_struct *tsk, int account)
{
if (IS_ENABLED(CONFIG_VMAP_STACK)) {