slabratetop(8)

💅 slabratetop(8) 💅

Okay so this is the manual for slabratetop, the Linux tool for watching the kernel's SLAB/SLUB memory allocation rate. It's from the System Manager's Manual, and it's the lowkey iconic sibling of slabtop. 🦋

✨ NAME ✨

slabratetop is a kernel SLAB/SLUB memory cache allocation rate top tool. It uses Linux BPF/bcc. 🧚

✨ SYNOPSIS ✨

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

✨ DESCRIPTION ✨

Bestie, this is top but for the rate of kernel SLAB/SLUB memory allocations. 💖 It works by tracing kmem_cache_alloc() calls, which is a super common interface for kernel memory allocation (SLAB or SLUB). It summarizes the rate and total bytes allocated by these calls per interval, so you can see the activity. 🔥

If you want the current static volume of the caches instead, check out slabtop(1). That one shows what's sitting there, while this one shows what's happening. 👑

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

Since this uses BPF, only the root user can use this tool. 💀 No root, no slabratetop, sorry bestie 🙈

✨ REQUIREMENTS ✨

You need CONFIG_BPF and bcc. 🫶

✨ OPTIONS ✨

• -C — Don't clear the screen. 🎀
• -r MAXROWS — Sets the maximum number of rows to print. The default is 20. 💜
• interval — The gap between updates, in seconds. ⭐
• count — How many interval summaries you want. 🍓

✨ EXAMPLES ✨

Summarize active kernel SLAB/SLUB calls (kmem_cache_alloc()), showing the top 20 caches every second. This is the main character default: 💅

# slabratetop

Don't clear the screen, and only show the top 8 rows. Clean and aesthetic. 🌈

# slabratetop -Cr 8

5 second summaries, 10 times only. Very structured, very organized. 🧚

# slabratetop 5 10

✨ FIELDS ✨

• loadavg — The contents of /proc/loadavg. 🌸
• CACHE — The kernel cache name. 💖
• ALLOCS — The number of allocations (number of calls). ✨
• BYTES — The total bytes allocated. 🔥

✨ OVERHEAD ✨

Heads up, bestie. If kmem_cache_alloc() is called at a high rate (eg, >100k/second), the overhead of this tool might start to be measurable. 😭 You can see the rate in the ALLOCS column of the output. 🦋

✨ SOURCE ✨

This is from bcc. 🫶 The repo lives at https://github.com/iovisor/bcc.

Also look in the bcc distribution for a companion _examples.txt file. It has example usage, output, and commentary for this tool, and it's giving very helpful energy. 🎀

✨ OS ✨

Linux 🐧

✨ STABILITY ✨

Unstable, still in development. 🙈 Handle with care, it's a work in progress.

✨ AUTHOR ✨

Brendan Gregg 👑

✨ SEE ALSO ✨

slabtop(1) 💜

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Okay that's the whole tea, bestie. This page came from the USER COMMANDS section, dated 2016-10-17, and it's all about slabratetop(8). Slay forever. 💅✨🦋