Re: [patch v11 0/6] support concurrent sync io for bfq on a specail occasion

[Paolo VALENTE]

> Il giorno 18 ott 2022, alle ore 06:00, Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> ha scritto:
> 
> Hi, Paolo
> 
> 在 2022/10/11 17:36, Yu Kuai 写道:
>>>>> Your patches seem ok to me now (thanks for you contribution and, above all, for your patience). I have only a high-level concern: what do you mean when you say that service guarantees are still preserved? What test did you run exactly? This point is very important to me. I'd like to see some convincing test with differentiated weights. In case you don't have other tools for executing such tests quickly, you may want to use the bandwidth-latency test in my simple S benchmark suite (for which I'm willing to help).
>>>> 
>>>> Is there any test that you wish me to try?
>>>> 
>>>> By the way, I think for the case that multiple groups are activaced, (
>>>> specifically num_groups_with_pendind_rqs > 1), io path in bfq is the
>>>> same with or without this patchset.
>> I just ran the test for one time, result is a liiter inconsistent, do
>> you think it's in the normal fluctuation range?
> 
> I rerun the manually test for 5 times, here is the average result:
> 
> without this patchset / with this patchset:
> 
> | --------------- | ------------- | ------------ | -------------- | ------------- | -------------- |
> | cg1 weight      | 10            | 20           | 30             | 40          | 50             |
> | cg2 weight      | 90            | 80           | 70             | 60          | 50             |
> | cg1 bw MiB/s    | 21.4 / 21.74  | 42.72 / 46.6 | 63.82 / 61.52  | 94.74 / 90.92 | 140 / 138.2    |
> | cg2 bw MiB/s    | 197.2 / 197.4 | 182 / 181.2  | 171.2 / 173.44 | 162 / 156.8   | 138.6 / 137.04 |
> | cg2 bw / cg1 bw | 9.22 / 9.08   | 4.26 / 3.89  | 2.68 / 2.82    | 1.71 / 1.72   | 0.99 / 0.99    |

Great!  Results are (statistically) the same, with and without your
patchset.  For me your patches are ok.  Thank you very much for this
contribution, and sorry again for my delay.

Acked-by: Paolo Valente <paolo.valente@xxxxxxxxxx>

Thanks,
Paolo

> 
>> test script:
>> fio -filename=/dev/nullb0 -ioengine=libaio -ioscheduler=bfq -jumjobs=1 -iodepth=64 -direct=1 -bs=4k -rw=randread -runtime=60 -name=test
>> without this patchset:
>> |                 |      |      |      |      |      |
>> | --------------- | ---- | ---- | ---- | ---- | ---- |
>> | cg1 weight      | 10   | 20   | 30   | 40   | 50   |
>> | cg2 weight      | 90   | 80   | 70   | 60   | 50   |
>> | cg1 bw MiB/s    | 25.8 | 51.0 | 80.1 | 90.5 | 138  |
>> | cg2 bw MiB/s    | 193  | 179  | 162  | 127  | 136  |
>> | cg2 bw / cg1 bw | 7.48 | 3.51 | 2.02 | 1.40 | 0.98 |
>> with this patchset
>> |                 |      |      |      |      |      |
>> | --------------- | ---- | ---- | ---- | ---- | ---- |
>> | cg1 weight      | 10   | 20   | 30   | 40   | 50   |
>> | cg2 weight      | 90   | 80   | 70   | 60   | 50   |
>> | cg1 bw MiB/s    | 21.5 | 43.9 | 62.7 | 87.4 | 136  |
>> | cg2 bw MiB/s    | 195  | 185  | 173  | 138  | 141  |
>> | cg2 bw / cg1 bw | 9.07 | 4.21 | 2.75 | 1.57 | 0.96 |
>>>> 
>>> 
>>> The tests cases you mentioned are ok for me (whatever tool or personal
>>> code you use to run them).  Just show me your results with and without
>>> your patchset applied.
>>> 
>>> Thanks,
>>> Paolo
>>> 
>>>> Thanks,
>>>> Kuai
>>>>> Thanks,
>>>>> Paolo
>>>>>> Previous versions:
>>>>>> RFC: https://lore.kernel.org/all/20211127101132.486806-1-yukuai3@xxxxxxxxxx/ 
>>>>>> v1: https://lore.kernel.org/all/20220305091205.4188398-1-yukuai3@xxxxxxxxxx/ 
>>>>>> v2: https://lore.kernel.org/all/20220416093753.3054696-1-yukuai3@xxxxxxxxxx/ 
>>>>>> v3: https://lore.kernel.org/all/20220427124722.48465-1-yukuai3@xxxxxxxxxx/
>>>>>> v4: https://lore.kernel.org/all/20220428111907.3635820-1-yukuai3@xxxxxxxxxx/ 
>>>>>> v5: https://lore.kernel.org/all/20220428120837.3737765-1-yukuai3@xxxxxxxxxx/ 
>>>>>> v6: https://lore.kernel.org/all/20220523131818.2798712-1-yukuai3@xxxxxxxxxx/ 
>>>>>> v7: https://lore.kernel.org/all/20220528095020.186970-1-yukuai3@xxxxxxxxxx/ 
>>>>>> 
>>>>>> 
>>>>>> Yu Kuai (6):
>>>>>>   block, bfq: support to track if bfqq has pending requests
>>>>>>   block, bfq: record how many queues have pending requests
>>>>>>   block, bfq: refactor the counting of 'num_groups_with_pending_reqs'
>>>>>>   block, bfq: do not idle if only one group is activated
>>>>>>   block, bfq: cleanup bfq_weights_tree add/remove apis
>>>>>>   block, bfq: cleanup __bfq_weights_tree_remove()
>>>>>> 
>>>>>> block/bfq-cgroup.c  | 10 +++++++
>>>>>> block/bfq-iosched.c | 71 +++++++--------------------------------------
>>>>>> block/bfq-iosched.h | 30 +++++++++----------
>>>>>> block/bfq-wf2q.c    | 69 ++++++++++++++++++++++++++-----------------
>>>>>> 4 files changed, 76 insertions(+), 104 deletions(-)
>>>>>> 
>>>>>> -- 
>>>>>> 2.31.1
>>>>>> 
>>>>> .
>>> 
>>> .
>>> 
>> .
>