On 10/26/2012 11:25 AM, Miao Xie wrote:
> On Fri, 26 Oct 2012 10:05:55 +0800, Liu Bo wrote:
>> On 10/26/2012 09:56 AM, Miao Xie wrote:
>>>> I can see the potential improvements brought by flushing inodes this way.
>>>>>
>>>>> But I don't think it makes much sense by making waiting process 
>>>>> multi-task,
>>>>> since even we spread wait order extents into different cpus, they just 
>>>>> occpied
>>>>> the cpu and went on waiting and scheduled then, I mean, the bottleneck is 
>>>>> on
>>>>> what we're waiting for.
>>> Thanks for your comment, I think only btrfs_run_ordered_operations(root, 0) 
>>> needn't
>>> wait for the works, the others must wait.
>>>
>>> The first reason is to avoid changing the semantic of those tree function. 
>>> The second
>>> reason is we have to wait for the completion of all works, if not, the file 
>>> data in
>>> snapshots may be different with the source suvolumes because the flush may 
>>> not end
>>> before the snapshot creation.
>>>
>>
>> Yes, it's right that they must wait for all workers to finish.
>>
>> But I don't mean that(sorry for my confusing words).
>>
>> IMO we don't need to let *btrfs_wait_ordered_extents()* run as multi-task.
> 
> It also need to be done by multi-task because btrfs_wait_ordered_extents() 
> doesn't imply
> that all the dirty pages in the ordered extent have been written into the 
> disk, that is
> it also need do lots of things before waiting for the event - 
> BTRFS_ORDERED_COMPLETE, so
> the multi-task process is useful, I think.
> 

Well, I missed the flushing part.

> Anyway, we need test to validate it.
> 
> Thanks
> Miao
> 
>>
>> thanks,
>> liubo
>>
>>
>>
>>
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to