Monitor resource contention with Pressure Stall Information

Pressure Gauge

Article from Issue 238/2020
Author(s):

Pressure Stall Information (PSI) is a new feature that gives users a better view of resource contention.

CPU, RAM, and I/O are the three most important computing resources. If these resources are depleted, processes start to fight for them and resource contention scenarios occur. To avoid these problems, it makes sense to monitor precisely what resources applications use in order to correctly dimension the hardware requirements and make optimal use of the existing hardware.

Smartphones can also benefit from this type of monitoring: when resources become scarce, phones often terminate programs in the background in order to offer the foreground application sufficient resources.

Load Average

Most administrators keep an eye on the load average to determine the extent to which a system is exposed to load. The uptime or top (Listing 1) commands both display the load average, reading the values from the /proc/loadavg file. The file contains five values (Line 6). In addition to the three load average values, the fourth value counts the current executable kernel scheduling entities and the fifth shows the process ID of the latest process created.

[...]

Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
 
SUBSCRIPTIONS
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • System Diagnosis Tools

    To check on the health of a Linux system, administrators can turn to vmstat, iostat, netstat, and ifstat. Or, you can just use the versatile dstat, which combines the features of several tools in a single package.

  • OOM Killer

    When a Linux system runs out of memory, a special agent, the out-of-memory killer, rushes to its aid. Facebook has now introduced its own OOM killer. What makes it different from its kernel-based counterpart? And what is an OOM killer really?

  • Command Line – Probing /proc

    The mysterious /proc virtual filesystem is a rich mine of information about everything in your system.

  • Optimizing Linux Performance

    When you're tuning up Linux performance, you need to keep an eye on a number of components and parameters. This article describes some techniques for optimizing performance by tuning TCP/IP, reducing latency, and configuring NUMA-aware systems. You'll also learn about CPU scheduling and memory management tuning.

  • Load Average

    What is the real meaning of those little “load average” values in the output of shell commands like procinfo and uptime, and what can you do with these numbers?

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

Learn More

News