slabratetop-bpfcc(8)

Usage

slabratetop [-h] [-C] [-r MAXROWS] [interval] [count]

Overview

This is top for the the rate of kernel SLAB/SLUB memory allocations. It works by tracing kmem_cache_alloc() calls, a commonly used interface for kernel memory allocation (SLAB or SLUB). It summarizes the rate and total bytes allocated of these calls per interval: the activity. Compare this to slabtop(1), which shows the current static volume of the caches.

This tool uses kernel dynamic tracing of the kmem_cache_alloc() function.

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

Requirements

CONFIG_BPF and bcc.

Options

-C: Don't clear the screen.

-r MAXROWS: Maximum number of rows to print. Default is 20.

`interval`	Interval between updates, seconds.
`count`	Number of interval summaries.

Examples

`Summarize active kernel SLAB/SLUB calls (kmem_cache_alloc()), showing the top 20 caches every second:`	# `slabratetop`
`Don't clear the screen, and top 8 rows only:`	# slabratetop -Cr 8
`5 second summaries, 10 times only:`	# slabratetop 5 10

Fields

`loadavg:`	The contents of /proc/loadavg
`CACHE`	Kernel cache name.
`ALLOCS`	Allocations (number of calls).
`BYTES`	Total bytes allocated.

Overhead

If kmem_cache_alloc() is called at a high rate (eg, >100k/second) the overhead of this tool might begin to be measurable. The rate can be seen in the ALLOCS column of the output.

Source

This is from bcc.

: 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.

Releases

Unchanged in 4 releases since Debian 10 (Buster).

10–13