slabratetop - Kernel SLAB/SLUB memory cache allocation rate top. Uses Linux BPF/bcc.
Contents
Description
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.
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-Cr8
5 second summaries, 10 times only:
# slabratetop510Fields
loadavg:
The contents of /proc/loadavg
CACHE Kernel cache name.
ALLOCS Allocations (number of calls).
BYTES Total bytes allocated.
Name
slabratetop - Kernel SLAB/SLUB memory cache allocation rate top. Uses Linux BPF/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.
Os
Linux
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.
Requirements
CONFIG_BPF and bcc.
See Also
slabtop(1) USER COMMANDS 2016-10-17 slabratetop(8)
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.
Stability
Unstable - in development.
Synopsis
slabratetop[-h][-C][-rMAXROWS][interval][count]
