Read next
Using systemtap to analyze latency of the kernel module function
In this post, we continue to explore how to use SystemTap to analyze the latency of the kernel module function. In the following example, we want to analyze the latency of the function "nfsd_vfs_write" from the kernel module "nfsd".
Deploy the SystemTap packages
Refer to this post to
Getting started with systemtap for Linux system profiling
Intro to SystemTap
SystemTap is a tracing and probing tool that allows users to study and monitor the activities of the operating system (particularly, the kernel) in fine detail. It provides information similar to the output of tools like netstat, ps, top, and iostat; however, SystemTap is designed to provide
Using ftrace to analyze latency of the kernel module function
In this example, we study the latency of the function "nfsd_vfs_write" from kernel module "nfsd".
ftrace configuration
The following ftrace options are used in this example. There are 8 nfsd processes to be traced.
* current_tracer: function_graph
* pids: 3591 3592 3593 3594 3595 3596 3597 3598
* filters: