Sunday, July 9, 2017

VRQ 0.96d release

VRQ 0.96d is released with the following changes

1. smt sensitive scheduling improvement, which reduce some migration overhead.
2. Fix livepatch compilation issue.

This is bug fix and smt sensitive scheduling improvement release.

Enjoy VRQ 0.96d for v4.12 kernel, :)

code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.12.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.12.y-vrq

All-in-one patch is available too.

BR Alfred 

Tuesday, July 4, 2017

VRQ 0.96c release

VRQ 0.96c is released with the following changes

1. Sync up mainline scheduler changes in 4.12
2. Clean up herder files.

This is just a sync-up release to bring VRQ to 4.12 kernel. Not new feature code is added in VRQ itself.

Enjoy VRQ 0.96c for v4.12 kernel, and unlock your SMT cpu ability with VRQ, :)

code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.12.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.12.y-vrq

All-in-one patch is available too.

BR Alfred 

Monday, July 3, 2017

VRQ 0.96b release

VRQ 0.96b is released with the following changes

1. smt sensitive scheduling v0.2, which fix issue with NR_CPUS > real cpu cores

Thank all for testing and finally bring SMT sensitive scheduling feature to VRQ. Feel free to test this release comparing to previous and enjoy the pleasure of unlocking the SMT capability, :)

I'm planing further improvement for SMT sensitive scheduling. Currently, I am not happy with implement code, there are duplicated code with migration code, and others. And it's late in this kernel release and time to look at sync-up works in 4.12 mainline.

Enjoy VRQ 0.96b for v4.11 kernel, and unlock your SMT cpu ability with VRQ, :)

code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.11.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.1.y-vrq

All-in-one patch is available too.

BR Alfred 

Wednesday, June 7, 2017

VRQ 0.96 release

Abandon this release due to lock-up issues reported by users, the lock-up is caused by "Lock strategy update" commit, which works well on my working machines and continue during my work on SMT sensitive scheduling, that make me believe it was good and stable.

New "Lock strategy update" debug patch will be posted here for testing. Once it is confirmed work well for other users,  the repined 096a will be released.

VRQ 0.96 is released with the following changes

1. Sync up cpufreq util usage.
2. Lock strategy update, which hopefully fix potential lock issue when task migrating.
3. SMT sensitive scheduling v0.1

Main feature in this release is the first version of SMT sensitive scheduling, which reduce 10s kernel compile benchmark on my test machine(original 7m17s) under 50% workload.
Or, you can easy to observe cpu usage changes when any physical cores available, scheduler will not put task to smt core. For example, if two tasks are running on a 2 cores 4 threads cpu, one will be on cpu 0 or 1, another will be on cpu 2 or 3.

Further improvement for SMT sensitive will be in next release. I'd see if any improvement/simplify can be made to current design.

Enjoy VRQ 0.96 for v4.11 kernel, and unlock your SMT cpu ability with VRQ, :)

code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.11.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.1.y-vrq

All-in-one patch is available too.

BR Alfred 

Thursday, May 4, 2017

VRQ 0.95b release

VRQ 0.95b is released with the following changes

1. Fix UP compilation issue with hrtick_enabled(), thanks jwh7 for reporting.
2. Sync up 4.11 mainline scheduler code changes.

This is mainly a sync-up release for 4.11 kernel. Please be notices that the frozen some time after suspend/resume issue still remains and it is confirmed that this also happen with vanilla kernel, so it's not caused by VRQ scheduler code. If suspend/resume is important for you, you may need to wait for the fix from mainline.

Enjoy VRQ 0.95b for v4.11 kernel, :)


code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.11.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.1.y-vrq

All-in-one patch is available too.

BR Alfred 

Friday, April 14, 2017

VRQ 0.95 release

VRQ 0.95 is released with the following changes

1. Fix compilation issue with CONFIG_CPUSETS(thanks Dzon reporting this)
2. Introduce hrtimer for task time slice expiration.
3. NO_HZ_FULL support
4. cpumask topology output in hex format.
5. use cpu_online_mask in sched_init_topology_cpumask(), this fix wrong topology setup for some system.

The most important feature in this release is introduce hrtimer for task time slice expiration and re-enable NO_HZ_FULL support.

For issues, Dazon also report his issue that unable to achieve full cpu utilization in kernel compilation. And I am still investigating, anyone else has similar issue could let me know.

In next release, SMT improvement is in the plan list.


Enjoy VRQ 0.95 for v4.10 kernel, :)


code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.10.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.10.y-vrq

All-in-one patch is available too.

BR Alfred 

Thursday, March 23, 2017

VRQ 0.94 release

VRQ 0.94 is released with the following changes

1. Remove duplicated code
2. Fix compilation issue with CONFIG_CPU_FREQ and CONFIG_IRQ_TIME_ACCOUNTING
3. Remove root_domain and sched_domain, which VRQ doesn't depend on. This reduce about 2k LOC of the scheduler code.

I have done some tests on SMT machine for the >100% regression issue, but for some kind of reason, I can't reproduce it, so now it is in the long-term watch list and let VRQ development going. Enjoy VRQ 0.94 for v4.10 kernel, :)

In next release, hrtimer and full no hz support are in the planning list.

code are available at
https://bitbucket.org/alfredchen/linux-gc/commits/branch/linux-4.10.y-vrq
and also
https://github.com/cchalpha/linux-gc/commits/linux-4.10.y-vrq

All-in-one patch is available too.

BR Alfred