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Subject: Re: [f2fs-dev] [PATCH v2 1/2] f2fs: introduce checkpoint=merge mount
 option
To:     Daeho Jeong <daeho43@gmail.com>, Chao Yu <yuchao0@huawei.com>
Cc:     Daeho Jeong <daehojeong@google.com>,
        Sungjong Seo <sj1557.seo@samsung.com>, kernel-team@android.com,
        linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
References: <20210114062302.3809664-1-daeho43@gmail.com>
 <965dc435-c0a0-36ca-7e97-c3aaa3831bff@huawei.com>
 <CACOAw_x4R+rWZbi4TQym_sWuyqOGRR5w3iOs1A+e+g=ZT5k7FQ@mail.gmail.com>
From:   Chao Yu <chao@kernel.org>
Message-ID: <b64dc9dd-9f22-cb91-c633-d7bbc74abf72@kernel.org>
Date:   Fri, 15 Jan 2021 22:33:37 +0800
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On 2021/1/15 22:00, Daeho Jeong wrote:
>> ktime_get() returns time based ns unit, in extreme scenario, average
>> time cp cost will overflow 32-bit variable, I doubt.
>>
> sum_diff is already turned into msec using ktime_ms_delta() above.

Yup, I missed ktime_ms_delta().


On 2021/1/15 22:23, Daeho Jeong wrote:
 >>> How about updating queued_ckpt and total_ckpt in batch, update atomic
 >>> variable one by one is low efficient.
 >>>
 >> You mean like using spin_lock()?
 >>
 > Ah, you mean like updating these values as much as the count of the
 > loop at once?

Correct. :)

Thanks,