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Message-ID: <1632d0e6-2d52-43b1-8a01-056231c0819d@bytedance.com>
Date:   Wed, 11 Oct 2023 23:42:30 +0800
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Subject: Re: [PATCH v4 09/10] maple_tree: Preserve the tree attributes when
 destroying maple tree
To:     Liam.Howlett@oracle.com
Cc:     maple-tree@lists.infradead.org, linux-mm@kvack.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org,
        Peng Zhang <zhangpeng.00@bytedance.com>, corbet@lwn.net,
        akpm@linux-foundation.org, willy@infradead.org, brauner@kernel.org,
        surenb@google.com, michael.christie@oracle.com, mjguzik@gmail.com,
        mathieu.desnoyers@efficios.com, npiggin@gmail.com,
        peterz@infradead.org, oliver.sang@intel.com, mst@redhat.com
References: <20231009090320.64565-1-zhangpeng.00@bytedance.com>
 <20231009090320.64565-10-zhangpeng.00@bytedance.com>
From:   Peng Zhang <zhangpeng.00@bytedance.com>
In-Reply-To: <20231009090320.64565-10-zhangpeng.00@bytedance.com>
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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);
>