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Message-ID: <ff9f1b54-5d50-a43d-62a7-3e1adadf1974@linux.alibaba.com>
Date:   Tue, 20 Sep 2022 09:54:23 +0800
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Subject: Re: [PATCH v1 1/2] mm/damon/sysfs: remove unnecessary variables
To:     SeongJae Park <sj@kernel.org>
Cc:     akpm@linux-foundation.org, damon@lists.linux.dev,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20220919170305.61335-1-sj@kernel.org>
From:   haoxin <xhao@linux.alibaba.com>
In-Reply-To: <20220919170305.61335-1-sj@kernel.org>
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在 2022/9/20 上午1:03, SeongJae Park 写道:
> On Mon, 19 Sep 2022 23:12:00 +0800 Xin Hao <xhao@linux.alibaba.com> wrote:
>
>> Just do a little change here, the 'err' variable really no need to stay
>> here.
>>
>> Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
>> ---
>>   mm/damon/sysfs.c | 6 ++----
>>   1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
>> index 0cca1909bf67..b852a75b9f39 100644
>> --- a/mm/damon/sysfs.c
>> +++ b/mm/damon/sysfs.c
>> @@ -1109,9 +1109,8 @@ static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
>>   {
>>   	struct damon_sysfs_region *region = container_of(kobj,
>>   			struct damon_sysfs_region, kobj);
>> -	int err = kstrtoul(buf, 0, &region->start);
>>
>> -	if (err)
>> +	if (kstrtoul(buf, 0, &region->start))
>>   		return -EINVAL;
> Good finding.  But, I'd like to let the user know why it really fails by giving
> them the error code that returned by 'kstrtoul()' here.  Let's keep the 'err'
> but return 'err' here.
Ok,  it make sense.
>
>>   	return count;
>>   }
>> @@ -1130,9 +1129,8 @@ static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
>>   {
>>   	struct damon_sysfs_region *region = container_of(kobj,
>>   			struct damon_sysfs_region, kobj);
>> -	int err = kstrtoul(buf, 0, &region->end);
>>
>> -	if (err)
>> +	if (kstrtoul(buf, 0, &region->end))
>>   		return -EINVAL;
> ditto.
>
>>   	return count;
>>   }
>> --
>> 2.31.0
>
> Thanks,
> SJ