Toro kernel

A dedicated kernel for multi-threading applications.

Sunday, August 26, 2018

Toro supports for try...except statement and user exceptions!

Hello folks! I just merged to master the commits to support the try..except statement. This allows user applications to handle exceptions. To do this, I had to switch to Linux RTL, which involved a lot of changes. I updated the wiki in case you want to try. In Windows, It is necessary to get a Freepascal cross-compiler from Windows to Linux that very well explained in the wiki. I hope you enjoy!

Matias Vara   

Thursday, August 16, 2018

Toro will be present in OSSEU18!

Hello folks! I am very happy to announce that Toro will be in OSSEU'18! For further information check http://sched.co/FxYD. I hope to see you all there!

Cheers, Matias.

Sunday, June 24, 2018

Reducing CPU usage on Toro guests, "The numbers"

Hello folks! I experimented around the last improvement of Toro regarding with reducing the energy consumption. I want to thank my very closed friend Cesar Bernardini for the experiments. In the tests, we compare an Ubuntu guest with a Toro guest on Qemu. We set up a 2 core machine with 256MB per core. To bench each kernel, we generate N http requests and then we stop, we repeat it every X time. Then, we measure the CPU usage of the Qemu process by using top. Then, we get the following graphs:

Toro without any improvement:
In this graph, you can see that Qemu's process is at 100% all the time. 

Toro with improvements:

With the improvements, Qemu's process is at 100%  only when traffic is received.  

Ubuntu guest:

When Ubuntu is on, i.e., when traffic is received, Qemu's process uses between ~40%...60%, then , when there is no trafic, cpu usage downs to around ~ 0%..15%.

In the next experiments, we incress the number of messages.

Toro guest:
When the number of messages is incressed, the Toro guest footprint does not change.

Ubuntu guest:
In the case of a Ubuntu guest, the cpu usage of the Qemu process reaches the 100% during traffic. This means that Ubuntu is correctly scaling the cpu usage on demand. 

Take Away Lessons:

- In production, CPU usage of Guests is important because the VCPUs are a shared resource
- The approach in Toro has reduced the CPU usage in a half, however a an overall power management solution must also scale the CPU, i.e., processor in P-State
- The approaches may depend on the hypervisor and its ability to emulate/virtualize the instructions related with power consumption, e.g., mwat/mcontrol

Thursday, May 24, 2018

Booting Toro in 123ms on QEMU-Lite

Hello folks! I have spent some time to port Toro to QEMU-Lite. This work is still very experimental and can be found in the branch feature-bootforqemu-lite. If you want to know more about QEMU-Lite check this great presentation. Roughly speaking,  QEMU-Lite is an improved version of QEMU, which is dedicated to boot a Linux kernel guest. QEMU-Lite improves the booting time by removing unnecessary steps in the booting process. For example, it removes the BIOS and the need of a bootloader. When QEMU jumps to the kernel code, the microprocessor is already in 64 bit long mode with paging enabled. To make Toro works on QEMU-Lite, I have to remove the whole bootloader and replace it by a simpler one that supports the Multiboot standar. So far I am only able to boot the application ToroHello.pas that takes only 123ms to boot. Future work will be to support multiprocessing so stay tuned!

Cheers, Matias.