| Message ID | 20231009090320.64565-10-zhangpeng.00@bytedance.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce __mt_dup() to improve the performance of fork() | expand |
在 2023/10/9 17:03, Peng Zhang 写道: > When destroying maple tree, preserve its attributes and then turn it > into an empty tree. This allows it to be reused without needing to be > reinitialized. > > Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> > --- > lib/maple_tree.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > index d5544382ff15..1745242092fb 100644 > --- a/lib/maple_tree.c > +++ b/lib/maple_tree.c > @@ -6775,7 +6775,7 @@ void __mt_destroy(struct maple_tree *mt) > if (xa_is_node(root)) > mte_destroy_walk(root, mt); > > - mt->ma_flags = 0; > + mt->ma_flags = mt_attr(mt)If I put everything into exit_mmap() for handling, this patch would not be necessary. But I think this patch is reasonable as it simply deletes all elements without requiring us to reinitialize the tree. What do you think? > } > EXPORT_SYMBOL_GPL(__mt_destroy); >
* Peng Zhang <zhangpeng.00@bytedance.com> [231011 11:42]: > > > 在 2023/10/9 17:03, Peng Zhang 写道: > > When destroying maple tree, preserve its attributes and then turn it > > into an empty tree. This allows it to be reused without needing to be > > reinitialized. > > > > Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> > > --- > > lib/maple_tree.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > > index d5544382ff15..1745242092fb 100644 > > --- a/lib/maple_tree.c > > +++ b/lib/maple_tree.c > > @@ -6775,7 +6775,7 @@ void __mt_destroy(struct maple_tree *mt) > > if (xa_is_node(root)) > > mte_destroy_walk(root, mt); > > - mt->ma_flags = 0; > > + mt->ma_flags = mt_attr(mt)If I put everything into exit_mmap() for handling, this patch would > not be necessary. But I think this patch is reasonable as it simply > deletes all elements without requiring us to reinitialize the tree. > What do you think? Willy and I had debated if we should do what you have here a long time ago. There was an issue with the next exit_mmap() that would not have arose with this change, which I was going to make before it was made unnecessary due to other changes in the caller. In the strict thinking of a destroy() call, I would expect the flags to not be spared, but doing this allows for an easy way to clear out a tree and resuse it as you have said. I'm happy to keep this patch. > > } > > EXPORT_SYMBOL_GPL(__mt_destroy);
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index d5544382ff15..1745242092fb 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -6775,7 +6775,7 @@ void __mt_destroy(struct maple_tree *mt) if (xa_is_node(root)) mte_destroy_walk(root, mt); - mt->ma_flags = 0; + mt->ma_flags = mt_attr(mt); } EXPORT_SYMBOL_GPL(__mt_destroy);
When destroying maple tree, preserve its attributes and then turn it into an empty tree. This allows it to be reused without needing to be reinitialized. Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> --- lib/maple_tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)