From:   "Huang, Ying" <ying.huang@intel.com>
To:     Tong Tiangen <tongtiangen@huawei.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        <wangkefeng.wang@huawei.com>, Guohanjun <guohanjun@huawei.com>
Subject: Re: [PATCH -next] memory tier: release the new_memtier in
 find_create_memory_tier()
In-Reply-To: <20230129040651.1329208-1-tongtiangen@huawei.com> (Tong Tiangen's
        message of "Sun, 29 Jan 2023 04:06:51 +0000")
References: <20230129040651.1329208-1-tongtiangen@huawei.com>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux)
Date:   Mon, 30 Jan 2023 16:17:55 +0800
Message-ID: <87edrctozw.fsf@yhuang6-desk2.ccr.corp.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ascii
Precedence: bulk

Tong Tiangen <tongtiangen@huawei.com> writes:

> In find_create_memory_tier(),  if failed to register device, then we should
> release new_memtier from the tier list and put device instead of memtier.
>
> Fixes: 9832fb87834e ("mm/demotion: expose memory tier details via sysfs")
> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
> ---
>  mm/memory-tiers.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
> index c734658c6242..e593e56e530b 100644
> --- a/mm/memory-tiers.c
> +++ b/mm/memory-tiers.c
> @@ -211,8 +211,8 @@ static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memty
>  
>  	ret = device_register(&new_memtier->dev);
>  	if (ret) {
> -		list_del(&memtier->list);
> -		put_device(&memtier->dev);
> +		list_del(&new_memtier->list);
> +		put_device(&new_memtier->dev);
>  		return ERR_PTR(ret);
>  	}
>  	memtier = new_memtier;

Good catch!  Thanks!

I think that this should be in stable since v6.1.

Best Regards,
Huang, Ying