Manual: swapin-bpfcc

swapin(8)					   System Manager's Manual					   swapin(8)

NAME
       swapin - Count swapins by process. Uses BCC/eBPF.

SYNOPSIS
       swapin

       -h, --help
	      show this help message and exit

       -T, --notime
	      do not show the timestamp (HH:MM:SS)

DESCRIPTION
       This tool counts swapins by process, to show which process is affected by swapping (if swap devices are in use). This
       can  explain a significant source of application latency, if it has began swapping due to memory pressure on the sys‐
       tem.

       This works by tracing the swap_readpage() kernel function using dynamic instrumentation. This tool may  need  mainte‐
       nance to keep working if that function changes in later kernels.

       Since this uses BPF, only the root user can use this tool.

REQUIREMENTS
       CONFIG_BPF and BCC.

EXAMPLES
       Count swapins by process, showing per-second summaries.
	      # swapin

FIELDS
       1st    The process name.

       2nd    The process ID.

       3rd    The count of swapins during that interval.

OVERHEAD
       The rate of swapins should be low (bounded by swapin device IOPS), such that the overhead of this tool is expected to
       be negligible.

SOURCE
       This originated as a bpftrace tool from the book "BPF Performance Tools", published by Addison Wesley (2019):

	      http://www.brendangregg.com/bpf-performance-tools-book.html

       See the book for more documentation on this tool.

       This version is in the BCC repository:

	      https://github.com/iovisor/bcc

       Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary
       for this tool.

OS
       Linux

STABILITY
       Unstable - in development.

AUTHOR
       Brendan Gregg

SEE ALSO
       swapon(8)

USER COMMANDS						 2019-07-05						   swapin(8)