Re: VFS hot tracking: How to calculate data temperature?

[Zhi Yong Wu]

On Sat, Nov 3, 2012 at 5:27 AM, Mingming.cao <cmm@xxxxxxxxxx> wrote:
> On Fri, 2012-11-02 at 14:38 +0800, Zhi Yong Wu wrote:
>> Here also has another question.
>>
>> How to save the file temperature among the umount to be able to
>> preserve the file tempreture after reboot?
>>
>> This above is the requirement from DB product.
>> I thought that we can save file temperature in its inode struct, that
>> is, add one new field in struct inode, then this info will be written
>> to disk with inode.
>>
>> Any comments or ideas are appreciated, thanks.
>>
>>
>
> Maybe could save the last file temperature with extended attributes.
It seems that only ext4 has the concept of extended attributes.

> Just save the per-inode temperature only for now.
>
> Mingming
>> On Fri, Nov 2, 2012 at 12:04 PM, Zhi Yong Wu <zwu.kernel@xxxxxxxxx> wrote:
>> > HI, guys
>> >
>> >    VFS hot tracking currently show result as below, and it is very
>> > strange and not nice.
>> >
>> > inode #279, reads 0, writes 1, avg read time 18446744073709551615,
>> > avg write time 5251566408153596, temp 109
>> >
>> > Do anyone know if there is one simpler but effective way to calculate
>> > data temperature?
>> >
>> > --
>> > Regards,
>> >
>> > Zhi Yong Wu
>>
>>
>>
>
>
>



-- 
Regards,

Zhi Yong Wu
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