What happens when the kernel is out of memory?
They usually, in that case, send an appropriate message to the log file and start shutting down. In the case when an application is running on Linux, the behavior is not that clear. Linux kernel was designed to allow the process to reserve more memory and make it available on the system.
How to troubleshoot what eats memory in Linux?
– Unix & Linux Stack Exchange How to troubleshoot what eats memory? I’m trying to figure out why memory consumption started to constantly increase on my server during the last hours. I’ve tried to find the cause on the application level, but no success. That is why now looking into possible server cause.
What kind of kernel does CentOS 7 use?
My server runs on CentOS 7 with the kernel 3.10.0-514.26.2.el7.x86_64 Finally, the issue was identified to be caused by a recently updated server library. The accepted answer is a good reminder, in the situation when you’re stressed out by the memory usage, to trace back what had been changed in your system before the issue appeared.
Why is memory management important in Linux kernel?
One of the most important responsibilities of Linux Kernel is optimal memory management. The first algorithms allowed for applications to allocate only memory which was physically available on the system, but it quickly turned out that this approach had significant drawbacks.
When does the kernel swap daemon become active?
The kernel swap daemon ( kswapd) is part of the Linux kernel, and converts used memory into free memory. The daemon becomes active when free memory on the device runs low. The Linux kernel maintains low and high free memory thresholds.
When does a process run out of memory?
The problem appears when the processes start, really utilizing all the reserved memory. The system then starts swapping and if they are not able to keep up with the need for memory, they call the OOM killer for help. What is the OOM killer?