If you haven’t heard about the RISC-V (pronounced “risk five”) processor, it’s an open-source (open-hardware, open-design) processor core created by the University of Berkeley. It exists in 32-bit, 64-bit, and 128-bit variants, although only 32- and 64-bit designs exist in practice. The news is full of stories about major hardware manufacturers (Western Digital, NVidia) looking at or choosing RISC-V cores for their product.
Continue reading Why you should care about RISC-V
A number of the SystemTap script examples in the newly released SystemTap 4.0 available in Fedora 28 and 29 have reduced the amount of time required to convert the scripts into running instrumentation by using the
This article discusses the particular changes made in the scripts and how you might also use this new tapset to make the instrumentation that monitors system calls smaller and more efficient. (This article is a follow-on to my previous article: Analyzing and reducing SystemTap’s startup cost for scripts.)
The key observation that triggered the creation of the
syscall_any tapset was a number of scripts that did not use the
syscall arguments. The scripts often used
syscall.*.return, but they were only concerned with the particular
syscall name and the return value. This type of information for all the system calls is available from the
sys_exit kernel tracepoints. Thus, rather than creating hundreds of kprobes for each of the individual functions implementing the various system calls, there are just a couple of tracepoints being used in their place.
Continue reading “Reducing the startup overhead of SystemTap monitoring scripts with syscall_any tapset”
Firewalld, the default firewall management tool in Red Hat Enterprise Linux and Fedora, has gained long sought support for nftables. This was announced in detail on firewalld’s project blog. The feature landed in the firewalld 0.6.0 release as the new default firewall backend.
The benefits of nftables have been outlined on the Red Hat Developer Blog:
There are many longstanding issues with firewalld that we can address with nftables that were not possible with the old iptables backend. The nftables backend allows the following improvements:
Continue reading “Firewalld: The Future is nftables”
Red Hat Container Development Kit (CDK) provides a single-node Red Hat OpenShift cluster designed to assist with containerized application development. This environment is like a production OpenShift environment, but it is designed to work on a single user’s computer. For this purpose, CDK runs Red Hat Enterprise Linux and Red Hat OpenShift Container Platform in a virtual machine.
Follow these steps to install CDK 3.4 on Fedora 28:
- Set up the virtualization environment.
- Install and configure CDK.
- Start CDK.
Below are details for performing these steps.
Continue reading “How to install Red Hat CDK 3.4 on Fedora 28”
In order to maximize performance of the Open vSwitch DPDK datapath, it pre-allocates hugepage memory. As a user you are responsible for telling Open vSwitch how much hugepage memory to pre-allocate. The question of exactly what value to use often arises. The answer is, it depends.
There is no simple answer as it depends on things like the MTU size of the ports, the MTU differences between ports, and whether those ports are on the same NUMA node. Just to complicate things a bit more, there are multiple overheads, and alignment and rounding need to be accounted for at various places in OVS-DPDK. Everything clear? OK, you can stop reading then!
However, if not, read on.
Continue reading “Open vSwitch-DPDK: How Much Hugepage Memory?”
I work at Red Hat on GCC, the GNU Compiler Collection.
My main focus for the last year has been on making GCC easier to use, so I thought I’d write about some of the C and C++ improvements I’ve made that are in the next major release of GCC, GCC 8. You can easily install GCC 8 on Red Hat Enterprise Linux 6 and 7 using Red Hat Developer Toolset (DTS). GCC 8 is the default compiler in Red Hat Enterprise Linux 8 Beta. GCC 8 is also available in Fedora 28 and later.
Continue reading “Usability improvements in GCC 8”
Compiled files, often called binaries, are a mainstay of modern computer systems. But it is often hard for system builders and users to find out more than just very basic information about these files. The Annobin project exists as means to answer questions like:
- How was this binary built?
- What testing was performed on the binary?
- What sources were used to make the binary ?
The Annobin project is an implementation of the Watermark specification , which details how to record extra information in a binary. One important feature of this specification is that it includes an address range for the information stored. This makes it possible to record the fact that part of a binary was compiled with one set of options and another part was recorded with a different set of options.
Continue reading “Annobin – Storing Extra Information in Binaries”
Red Hat Container Development Kit (CDK) provides a Container Development Environment (CDE) that allows users to build a virtualized environment for OpenShift. This environment is similar to the user’s production environment and does not need other hardware or a physical cluster. CDK is designed to work on a single user’s desktop computer.
Continue reading “Running CDK 3.0 on Fedora 25”
Why use RPMs (distribution packages in general) at all ?!
Distribution RPMs enables you to get signed curated content, with security updates, bug fixes, general updates, some level of testing, and known ways of reproducing the build locally. Of course, it has its cost mostly in the package size overhead and packaging infrastructure overhead (yum, dnf, apt….).
Continue reading “Basics of Go in Fedora”
In 2016, many improvements happened in the ABI static analysis framework that is Libabigail. In this article we’ll present how fedabipkgdiff, a new Libabigail tool can help Fedora users, developers and others to analyze ABI changes of libraries carried by packages of the distribution.
Continue reading “ABI change analysis of Fedora packages”