On Thu, Jan 19, 2012 at 5:14 PM, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> On 19/01/12 13:33, Jaehoon Chung wrote:
>> Hi Adrian.
>>
>> On 01/19/2012 07:21 PM, Adrian Hunter wrote:
>>
>>> On 19/01/12 07:29, Jaehoon Chung wrote:
>>>> Enable eMMC background operations (BKOPS) feature.
>>>>
>>>> If URGENT_BKOPS is set after a response, note that BKOPS
>>>> are required. After all I/O requests are finished, run
>>>> BKOPS if required. Should read/write operations be requested
>>>> during BKOPS, first issue HPI to interrupt the ongoing BKOPS
>>>> and then service the request.
>>>
>>> This still does not seem to address my earlier comment which was:
>>>
>>> The main problem with bkops is:
>>>
>>> If the status is at level 3 ("critical"), some operations
>>> may extend beyond their original timeouts due to maintenance
>>> operations which cannot be delayed anymore.
>>>
>>> This means:
>>>
>>> 1. at level 3 either bkops are run or the timeout of the next
>>> (data?) operation is extended
>>>
>>> 2. at level 3 either the bkops must not be interrupted or the
>>> level must be rechecked after interruption and bkops run again
>>> if the level is still 3, or the timeout of the next (data?)
>>> operation is extended
>>>
>>
>> This patch didn't issue the HPI when bkops-status is level2-3
>> (URGENT_BKOPS case).
>> I didn't understand that must be recheck?? it's case of using HPI..?
>> If HPI didn't issue,though must be recheck bkops status?
>> And level-1 control should be considered for future-work.
>> I will also modify the patch comment..it's confused something.
>
> 1. Say there are 2 write requests queued and after the first write request
> the bkops level is 3. That means the 2nd write request may timeout because
> the normal timeout rules do not apply.
>
> Thus:
> 1. at level 3 either bkops are run or the timeout of the next
> (data?) operation is extended
>
> 2. Say you are running bkops because the level was 3 and a write request
> arrives. You use HPI to interrupt the bkops, but the bkops level may still
> be 3, so the write request may timeout. Hence:
>
> 2. at level 3 either the bkops must not be interrupted or the
> level must be rechecked after interruption and bkops run again
> if the level is still 3, or the timeout of the next (data?)
> operation is extended
>
A naive question perhaps, but don't the current timeout values include
sufficient
buffer to do implicit garbage collection anyways ?
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