Currently, we free the avc objects with holding a lock. To minimize
lock hold time, we just move the avc objects to another list
with holding a lock. Then, iterate them and free objects without holding
a lock. This makes lock hold time minimized.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
diff --git a/mm/rmap.c b/mm/rmap.c
index 1603f64..9cfb282 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -330,6 +330,7 @@ void unlink_anon_vmas(struct vm_area_struct *vma)
{
struct anon_vma_chain *avc, *next;
struct anon_vma *root = NULL;
+ LIST_HEAD(avc_list);
/*
* Unlink each anon_vma chained to the VMA. This list is ordered
@@ -348,10 +349,14 @@ void unlink_anon_vmas(struct vm_area_struct *vma)
if (RB_EMPTY_ROOT(&anon_vma->rb_root))
continue;
+ list_move(&avc->same_vma, &avc_list);
+ }
+ unlock_anon_vma_root(root);
+
+ list_for_each_entry_safe(avc, next, &avc_list, same_vma) {
list_del(&avc->same_vma);
anon_vma_chain_free(avc);
}
- unlock_anon_vma_root(root);
/*
* Iterate the list once more, it now only contains empty and unlinked
@@ -363,7 +368,6 @@ void unlink_anon_vmas(struct vm_area_struct *vma)
put_anon_vma(anon_vma);
- list_del(&avc->same_vma);
anon_vma_chain_free(avc);
}
}
--
1.7.9.5
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>