Andrew Morton wrote:
> Con Kolivas <[email protected]> wrote:
>>
>> All the io-write based loads were affected.
>
> Yup. Mainly because the large queue increases truncate latencies.
Are there loads that do benefit from large queues? If so, does it make
sense to use truncate impact (something like a decaying average of truncate
time per interval) to control the size of the queues on the fly?
Comments
Ed Tomlinson
Ed Tomlinson wrote:
>Andrew Morton wrote:
>
>
>>Con Kolivas <[email protected]> wrote:
>>
>>>All the io-write based loads were affected.
>>>
>>Yup. Mainly because the large queue increases truncate latencies.
>>
>
>Are there loads that do benefit from large queues? If so, does it make
>sense to use truncate impact (something like a decaying average of truncate
>time per interval) to control the size of the queues on the fly?
>
I'll post some more benchmarks, but I have found that loads with
lots of IO streams. Those with more than about 1/2 as many IO streams
as request slots start to show improvements. I don't think changing
the size of the queues on the fly would be any good. They can be
made runtime tunable quite easily now, which is a good bad solution.