slabratetop - Kernel SLAB/SLUB memory cache allocation rate top. Uses Linux BPF/bcc. slabratetop [-h] [-C] [-r MAXROWS] [interval] [count] 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. CONFIG_BPF and bcc.

-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.

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

loadavg: The contents of /proc/loadavg

CACHE Kernel cache name.

ALLOCS Allocations (number of calls).

BYTES Total bytes allocated.

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. 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.

Linux Unstable - in development. Brendan Gregg slabtop(1)