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

[Yu Kuai]

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    |

> 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
> > > > .
> >
> > .
>
> .