Kernel retrieve timeslice used how to#

11.4 Using Custom Subsampling Techniques.7.0.27 Multivariate Adaptive Regression Splines.5.9 Fitting Models Without Parameter Tuning.5.8 Exploring and Comparing Resampling Distributions.5.7 Extracting Predictions and Class Probabilities.5.1 Model Training and Parameter Tuning.4.4 Simple Splitting with Important Groups.4.1 Simple Splitting Based on the Outcome.3.2 Zero- and Near Zero-Variance Predictors.And it’s yet one more example of how a little CLI magic can make life in the GUI a little nicer. Sysctl is not a command you’re apt to use regularly (unless you’re a sysadmin like that Brian Jones fella), but it sure is handy to have around when you need it. Not only can you modify kernel parameters one at a time as I did, you can save parameter values in a file (like /etc/nf) and load them all at once by pointing sysctl at the file with the -p option.

The images moved more crisply and the program issued alarms for movement that it had missed before. To increase the allotment, I simply typed:Īfter resetting the ZoneMinder option for the number of buffers, I restarted the app, and lo and behold, it worked without error. I decided to increase the total (kernel.shmmax) shared memory allowed to see if I could run ZoneMinder with larger buffers. I had to cut that number to 50 to get it working with one camera, and cut it again to 25 to get it working with two. The default number of image buffers in Philip Coombes’ great Linux home security camera app ZoneMinder is 100. Sysctl replied with a long list of keywords and values, including these: After learning that you could use sysctl to write new values for a long list of kernel, I decided to query sysctl for what it knew about tunable parameters. I read through the man pages for sysctl a time or two. In fact, in an article for, IBM’s Sachin Agrawal wrote “shared memory is probably the most efficient inter-process communication channel provided by all modern operating systems.” But when you need to share an area in memory in order for programs to work together in harmony, it’s a good thing. Normally, the operating system stands guard over memory to make sure one program doesn’t get into another’s space. It’s simply a way to allow multiple programs to share the same areas of memory. Shared memory, if you don’t know, has nothing at all to do with Jung’s theory of a “collective unconscious” or Joseph Campbell’s notions about myth and symbols. So I asked the man what he thought of sysctl, and sure enough, it looked like the right tool for the job. I started asking around as to how you could do that, and Brian Jones - the no-goodski sysadmin who writes the weekly SysAdmin-to-SysAdmin column here on - pointed me towards the sysctl command.

Kernel retrieve timeslice used how to#

Naturally, I took the easy way out and did it through the application rather than learn how to do it the correct way: increasing the amount of shared memory available. I could change the default configuration and reduce the number of buffers used to store video images, and that would reduce the amount of shared memory required. When I was installing an application, I got errors that told me it couldn’t find sufficient shared memory. That’s really cool, because I had need to do that recently.

Man tells us that by using sysctl we can “configure kernel parameters at runtime.”

Why? Because I just used sysctl for the first time today and I’m not exactly what you would call an expert on the subject. Let’s bust open a console.Let’s start with man sysctl instead of saving it for the last, as we usually do. You lily-livered GUI lizards who get chills at the thought of entering commands at the CLI might want to call your mommy over to sit with you and hold your hand this week, because we’re going to become one with the kernel.