After visiting FISL this summer, my travels have now taken me to LinuxCon NA 2016 in Toronto.
As every knows, theeverywhere. Several companies are working in this market, there are even hardware optimized for getting the best performance on containers
esides containers there were several different subjects had more contact w:
memory-driven computers, workqueues, bluetooth, graphics, file systems, power saving (check the talk highlights below).
I also met several amazing people working in different fields and contributing with the free software community.
The infrastructure of the event was great, wifi worked everywhere. There was breakfast for attendees and small breaks during the day.
In the Hall there were several couches and tables and the conference rooms were great.
morning there were keynotes that were hosted in a big fancy room. These were also streamed to the hall so other people could watch.
In he afternoon there were several talks happening in parallel in smaller rooms.
The women lunch:
n the first day there was a women's only lunch event promoted by Intel, which was populated by 100+ women from the tech field. I've never seen so many of us reunited like that
It was a great event to socialize and where everybody works. Several of them work directly with coding, but not the majority.
It was a pleasure to meet everyone and I am looking forward to see even more women in tech.
In this booth I met The Machine, which is based in a Memory-driven computer architecture that promises revolutionize how we know computers today.
The main memory is based in memristors, which can be viewed as a non-volatile RAM, so instead of having our basic model of Caches/Main Memory/Disk we would only have one memory based on memristors, all connected through a photonic fabric instead of a copper bus.
This changes our current programing model. HP have a github available with a framework where you can emulate the hardware, test and start programing for it.
Diamanti is a company that offers a hardware based solution to optimize containers and virtual environments, as mentioned in my NVMe post, I am working in a patch to optimize performance of shared NVMe device for a guest system in software while Diamanti, instead of sharing a NVMe device by software, make their hardware pretend there are multiple NVMe devices and they attach each of this devices directly to a container or virtual machine, thus from a software point of view, the container controls the device without having the VMM interfering.
They also do the same this for other peripherals beside NVMe as network cards.
Besides the Linux distribution (Ubuntu), this booth was presenting Juju, which is a tool to manage your services in the cloud, and also LXD, an hypervisor for containers
As most of you know, the Docker project is a great tool to create containers, which are something in the middle of a virtual machine and a chroot, it uses the kernel from the host.
Docker is also the name of the company (I thought is was only the name of the project) and they use LXC as base to create containers.
The company provides services for other companies using the Docker project as setting up the infrastructure, setting a private Docker Hub, providing support, etc.
Why Microsoft was in LinuxCon? To declare its love for Linux :)
In this booth I stickers written "Microsoft loves Linux" they decided to stop fighting old battles and be friends with Linux in the server market.
CoreOs is a Linux distribution meant to be a lightweight host system for docker containers.
Kubernetes is a tool for managing containers, automating deployment and scaling. So used in conjunction with CoreOs is a good match.
Btrfs with High Speed Devices - Chris Mason, Facebook:
Current the maintainer of Btrfs, Chris Mason talked about this file system, tools to debug and how to identify bottlenecks.
One of the bottlenecks was btree locking, where he presented a patch that ha a new locking scheme that optimize the file system.
Open Source Bluetooth Device Firmware for IoT and Makers - Marcel Holtmann, Intel:
In this talk, Marcel Hltmann gave a great overview of the Bluetooth stack and mentioned that Bluetooth 5.0 is coming mesh network.
As he is the maintainer of the Bluetooth stack on Linux, he talked about BlueZ and other Bluetooth tools in Linux.
For IoT and Makers who usually use an nRF51/nRF52 Bluetooth chip with the proprietary SoftDevice firmware, Marcel talked about how we could use Zyphis or MyNewt (which are open source) instead of SoftDevice and how he managed to get it working on Arduino 101.
Async Execution with Workqueue - Bhaktipriya Shridhar, Linux Kernel
Bhaktipriya Shridhar gave a talk about her Outreachy project on workqueues and how she managed to migrated several drivers from the old API to the new one.
Workqueues is a mechanism in Linux Kernel to execute pieces of code in asynchronous fashion, in short: if you have a function to execute and you don't want to wait for it to return, you can add it in the workqueue.
Internally, the kernel has two API's, the old one, with several issues as proliferation of kernel threads (it could run out of process IDs before even executing user space), deadlocks (if wasn't handled correctly) and unnecessary context switches. And the new API, the Concurrency Managed Workqueue (cmwq), which solves most of these issues.
Check her slides here: http://events.linuxfoundation.org/sites/events/files/slides/Async%20execution%20with%20wqs.pdf
Kernel Internship Report and Outreachy Panel - Moderated by Karen Sandler, Software Freedom Conservancy; Helen Fornazier, Rik Van Riel & Bhaktipriya Shridhar
Outreachy is 3 month internship meant to promote the presence of minorities in free software community.
If you know what GSoC is, Outreachy is similar with small differences in the projects (not necessary about coding), the selection phase, who can participate, etc.
In the panel we had 2 former mentors Rik Van Riel and Tiffany Antopolski (who is also a former intern), Bhaktipriya Shridhar (current intern in the linux kernel), as former intern and Karen Sandler as host and part of the organization of the Outreachy program at Software Freedom Conservancy.
Each one shared experience as a mentor or as an intern.
CPUfreq and The Scheduler: Revolution in CPU Power Management - Rafael J. Wysocki, Intel OTC
To save power when the system can't go idle, CPUFreq can decrease or increase the clock frequency of the CPU based in the current work load.
Rafael Wysocki (ACPI core maintainer) explained the architecture of the old system that was based on timers, that would sample the load from time to time and update the clock frequency accordingly. he new system provides a much better result by using a Scheduler-driven mechanism instead of timers, using data from the scheduler to make decisions on the next frequency.
Check his slides here: http://events.linuxfoundation.org/sites/events/files/slides/cpufreq_and_scheduler_0.pdf
Bringing Android Explicit Fencing to Mainline - Gustavo Padovan, Collabora Ltd.
In this talk, Gustavo Padovan explained how graphic fences are exposed to userspace to synchronize buffer sharing and increase performance compared to the implicit fencing where userspace is not aware.
Check his slides here: http://events.linuxfoundation.org/sites/events/files/slides/Explicit-Fencing_Talk.pdf
The gala party:
In the last day we had a great gala
I had the pleasure to have a great conversation with Eduardo Habkost from Red Hat who work with virtualization for 10+ years and me a great explanation on how Qemu connects with KVM.