Project C v5.12-r1 release

 

Project C v5.12-r1 is released.

It was released with previous reported issue fixes. Enjoy it.

Project C v5.12-r0 release

Project C v5.12-r0 is released.

Sync-up release, more issue fixes will be in next release.

Project C v5.11-r3 release

Project C v5.11-r3 is released.

Sync-up work for v5.12 will begin soon. ;)

Project C v5.11-r2 release

Project C v5.11-r2 is released.

It's a user driven release, thanks who take part into it.

Project C v5.11-r0 release

 

Project C v5.11-r0 is released.

First release for 5.11, a lot of mainline code changes and adaptation, there is still known minor issue, but it should work.

 And, Happy Chinese New Year!

Project C v5.10-r2 release

Project C v5.10-r2 is released.

Fix compilation errors before the new year. :)

Project C v5.10-r1 release

Project C v5.10-r1 is released. 

This is a Xmas release of project c, last two issues raised in previous blog msg is not yet fixed. It is encouraged to create bug report/issue in gitlab, they will be better traced with the code.

2020 is a such different year which impact everyone in the world. Fortunately I can live more closer to normal live but still have face mask on for almost a year now, and I guess it will continue in 2021.

In this year, the development of bmq/pds schedulers still continue, and they make together into project c. To be honest, if I have more WFH time, I could put more time into this project, :) . In short, it is normal year for my scheduler development project. And, hopefully it give you a normal thing feeling in this abnormal year.

Merry Xmas and Happy new year.  Take care yourself and others.

Project C v5.10-r0 release

Project C v5.10-r0 is released.

Project C announcement

BMQ scheduler has been development for more than one year. And it has accomplished the ambition when it was setup to be. As a simple scheduler, BMQ is now stable for several kernel release and less feature is added from release to release. It is now in maintenance mode.

When searching for idea about cpu scheduling, PDS, which has been exiled since BMQ, is still the most potential one, and the one most close to BMQ(in code level and performance level). Several very early improvement idea has been drafted after the reviewing of the latest PDS(kernel 5.0). So, PDS will be picked up again, and it is going to share same code base of BMQ. That comes Project C.

Project C ambitions
1. Based on BMQ code base, provide common alternative cpu scheduler code for linux kernel.
2. Provide single patch set for BMQ and PDS, switch at kernel configuration.
3. Maintenance BMQ
4. Continuous improvement on PDS till it enter maintenance mode.

Here is the recent Project C planing in the incoming kernel release cycle
5.7   Refactor BMQ into Project C infrastructure. 
5.8   Recreate PDS based on Project C code base.
5.9   PDS beta.
5.10 PDS official release.
5.11 PDS continuous improvement. 

Project C has no deadline defined, but may last for a year.

And the last thing, C for "Cross".

PDS 0.99o release

PDS 0.99o is released with the following changes

1. Sync-up changes from mainline scheduler code.

This is the first PDS release for kernel 5.0.

Enjoy PDS 0.99o for v5.0 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too. 

PDS 0.99n release

PDS 0.99n is released with the following changes

1. Fix hrtick_start() too short for new tasks.

This is a bug fix release before kernel 5.0.

Enjoy PDS 0.99n for v4.20 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too. 

PDS 0.99m release

PDS 0.99m is released with the following changes

1. [Sync] f29a8be0e5d2 cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM

This is a sync-up release for 4.20.8+, and should be the last PDS for 4.20.

Enjoy PDS 0.99m for v4.20 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too. 

PDS 0.99l release

PDS 0.99l is released with the following changes

1. Fix wrong task priority issue. Now, RT(non-normal) tasks has their proper priority, can be verified by 'RT' priority shown in top/htop.

This is a bug fix release.

Enjoy PDS 0.99l for v4.20 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too. 

PDS 0.99k release

PDS 0.99k is released with the following changes

1. Use exported task_rq_lock/unlock(). These mainline API has been implemented and exported in PDS, so we can use them in other modules to minimized PDS code changes.
2. Optimize pds_skiplist_random_level().
3. Rework SCHED_ISO and non-root user can switch task among ISO/NORMAL/BATCH/IDLE.
 
The most important change in this release is the rework of ISO policy in PDS

"""
    SCHED_ISO tasks now have higher priority to be picked up and run than
    SCHED_NORMAL tasks. When their remaining time slice(default max 4ms in
    PDS) run out, they will degrade to SCHED_NORMAL(and nice level kicks
    in). The degradation will be continued when they still hungry for cpu.

    The above design makes SCHED_ISO good for interactivity but not cpu
    consumption tasks.
"""
And now, normal users can set task policy ISO/NORMAL/BATCH/IDLE freely without root permission. You are encouraged to test any interactive task in PDS new ISO policy(such as gaming, media playback, browsing web ...), and feedback will be welcome.

Enjoy PDS 0.99k for v4.20 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too. 

PDS 0.99j release

PDS 0.99j is released with the following changes

1. Fix missing mainline scheduler API for psi.
2. Fix fail to build on ppc64 arch. This issue was reported to PDS-mq repository 3 months ago, and I have missed the notification, very sorry about that.
3. Several code implement level optimization.
 
This is the happy new year release of PDS, include bug fixes and optimization. Thanks for your supporting PDS in 2018. PDS achieved stability, feature and performance this year.

Looking forward in the incoming 2019, there is not much pending features in my list, and after those features, PDS may very close to 1.0 release(thus it just a release number). So, sometime next year, PDS development will slow down(it will still sync with mainline release and bug fixes), I will switch to another scheduler project, hopefully ideas can be inspired from each other projects and benefit from it.

Enjoy PDS 0.99j for v4.20 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too.

PDS 0.99i release

PDS 0.99i is released with the following changes

1. Sync-up with mainline 4.20 scheduler code changes.

Xmas gift comes as promised and here is the first PDS release for 4.20, just the sync-up code changes added. The code has been run since -rc7 for about a week. So there should be no surprise in it, :D
But if you are seeking for surprise, well, there will be optimization code changes for the next release before the new year!

Enjoy PDS 0.99i for v4.20 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too.

PDS 0.99h release

PDS 0.99h is released with the following changes

1. Fix cpu hot-plug Oops. Thanks @pf's report(again).
2. Rework time_slice_expired().  Simplified and unified task deadline reflash

This should be the last PDS release for 4.19 kernel. Other code implement level optimization are pending for 4.20. Hopefully kernel 4.20 and PDS for 4.20 could be on time as Xmas gift.

Enjoy PDS 0.99h for v4.19 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too.

EDIT: Pls also checkout the emergency fix at  https://gitlab.com/alfredchen/linux-pds/commit/fae1a3c0fbe60b7edf6d8aac6b838520da68f9e4

4.20 is coming out soon, so there is no plan to dump up version for 4.19 again.

PDS 0.99g release

PDS 0.99g is released with the following changes

1. [Sync] c5511d03ec09 sched/smt: Make sched_smt_present track topology. A lot of changes from mainline in v4.19.7 and the incoming 4.20 kernel release.
2. Fix smt boot up crash. This fix a bug in 0.99f PDS release(not related to mainline code changes), thanks @pf's report and help for debugging.

This is a sync-up and bug-fix release.

Enjoy PDS 0.99g for v4.19 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too.

PDS 0.99f release

PDS 0.99f is released with the following changes

1. Remove load balance code from scheduler_tick(). Based on recent code change and testing, looks like there is no need to check load balance in scheduler_tick() any more.
2. Default 4ms rr_interal. Trade off performance for interactivity improvement.
3. Rework sibling group balance. Reduce the overhead in sibling group balance by rework the code path.

This release includes balance code rework, and will be the biggest change in this kernel cycle. Please give it a try and feedback will be welcome.

Enjoy PDS 0.99f for v4.19 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too.

PDS 0.99e release

PDS 0.99e is released with the following changes

1. Fix sched_fork() time slice fairness. Simplify the code and fairness first.
2. Refine take_other_rq_task() code path.
3. Remove cpumask_weight() in best_mask_cpu().

This release includes minor changes. It's good to have such small change release before the big one.

Enjoy PDS 0.99e for v4.19 kernel, :)

Code are available at https://gitlab.com/alfredchen/linux-pds
All-in-one patch is available too.