Ants are known to leave invisible pheromones on their paths in order to inform both themselves and their fellow ants where to go to find food or signal that a path leads to danger. In biology, this phenomenon is known as stigmergy: the act of modifying your environment to manipulate the future behaviour of yourself or others. From the Wikipedia article:
Stigmergy (/ˈstɪɡmərdʒi/ STIG-mər-jee) is a mechanism of indirect coordination, through the environment, between agents or actions. The principle is that the trace left in the environment by an individual action stimulates the performance of a succeeding action by the same or different agent. Agents that respond to traces in the environment receive positive fitness benefits, reinforcing the likelihood of these behaviors becoming fixed within a population over time.
For ants in particular, stigmergy is useful as it alleviates the need for memory and more direct communication; instead of broadcasting a signal about where a new source of food has been found, you can instead just leave a breadcrumb trail of pheromones that will naturally lead your community to the food.
We humans also use stigmergy in a lot of ways: most notably, we write things down. From post-it notes posted on the fridge to remind ourselves to buy more cheese to writing books that can potentially influence the behaviour of a whole future generation of young people.
Let's face it: We don't have infinite brains and we need to somehow alleviate the need to remember everything. If you remember the movie Memento, the protagonist Leonard has lost his ability to form new long-term memories and relies on stigmergy to inform his future actions; everything that's important he writes down in a place he's sure to come across it again when needed. His most important discoveries he turns into tattoos that he cannot lose or avoid seeing when he wakes up in the morning.
Perhaps a biologist would object and say this is stretching the definition of stigmergy, but I contest that it fits: leaving a trace in the environment in order to stimulate a future action.
For stigmergy to be effective, it must be placed in the right location so that whoever comes across it will perform the correct action at that time. If we return briefly to the shopping list example, we typically keep the list close to the fridge because that is often where we are when we need to write something down -- or when we go to check what we need to buy.
Let's take an example from computing: Have you ever seen a line at the top of a file that says "AUTOMATICALLY GENERATED; DON'T MODIFY THIS"? Well, that's stigmergy. Somebody made sure that line would be there in order to influence the behaviour of whomever came across that file. A little note from the past placed in the environment to manipulate future actions.
In programming, stigmergy mainly manifests as comments scattered throughout the code -- the most common form is perhaps leaving a comment to explain what a piece of code is there to do, where we know somebody will find it and, hopefully, be able to make use of it. Another one is leaving a "TODO" comment where something isn't quite finished -- you may not know that a piece of code isn't handling some corner case just by glancing at it, but a "TODO" comment stands out and may even contain enough information to complete the implementation. In other cases, we see the opposite: "here be dragons"-type comments instructing the reader not to change something, perhaps because the code is known to be complicated, complex, brittle, or prone to breaking.
Stigmergy is a powerful idea, and once you are aware of it you can consciously make use of it to help yourself and others down the line. We're not robotic ants and we can make deliberate choices regarding when, where, and how we modify our environment in order to most effectively influence future behaviour.
Linux Plumbers Conference 2022 is pleased to host the Power Management and Thermal Control Microconference
The Power Management and Thermal Control microconference focuses on frameworks related to power management and thermal control, CPU and device power-management mechanisms, and thermal-control methods. In particular, we are interested in extending the energy-efficient scheduling concept beyond the energy-aware scheduling (EAS), improving the thermal control framework in the kernel to cover more use cases and making system-wide suspend (and power management in general) more robust.
The goal is to facilitate cross-framework and cross-platform discussions that can help improve energy-awareness and thermal control in Linux.
Suggested topics:
Please come and join us in the discussion about keeping your systems cool.
We hope to see you there!
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Debian 10 will also receive Long Term Support for five years after its initial release with support ending on June 30, 2024. The supported architectures will be announced at a later date.
Linux Plumbers Conference 2022 is pleased to host the System Boot and Security Microconference
In the fourth year in a row, System Boot and Security microconference is are going to bring together people interested in the firmware, bootloaders, system boot, security, etc., and discuss all these topics. This year we would particularly like to focus on better communication and closer cooperation between different Free Software and Open Source projects. In the past we have seen that the lack of cooperation’s between projects very often delays introduction of very interesting and important features with TrenchBoot being very prominent example.
The System Boot and Security MC is very important to improve such communication and cooperation, but it is not limited to this kind of problems. We would like to encourage all stakeholders to bring and discuss issues that they encounter in the broad sense of system boot and security.
Expected topics:
Please come and join us in the discussion about how to keep your system secure from the very boot.
We hope to see you there!
Theo de Raadt (deraadt@) committed the change:
CVSROOT: /cvs Module name: src Changes by: deraadt@cvs.openbsd.org 2022/07/02 11:21:32 Modified files: sbin/dhclient : dhclient.c Log message: dhclient(8) has been undergoing replacement with "ifconfig xxx inet auto" for a couple of years, backed by dhcpleased(8), which provides much better dns handling. The next step is to make the dhclient simply execve ifconfig in that way, and provide syslog warnings about deprecated options along the way. This way, we can find the last few dhclient users, and what they are missing. ok florian krw