watching bloated slabs

watching bloated slabs

[William Lee Irwin III]

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I got to wondering about how bloated various slabs were, and how
perhaps to track their bloatedness over time. So I brewed up a couple
of scripts to help more closely observe their humongous bloatedness.

bloatmon just cooks some slab stats so it grinds out lines with the
cache name, amount of space granted to callers, amount of space parked
in the slab, and percent utilization.

bloatmeter drives bloatmon in a loop, sorts its output by %util, and
chops off the output at 22 lines to put the most underutilized (and
hence bloated) slabs up top.

Cheers,
Bill

[-- Attachment #2: bloatmon --]
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#!/usr/bin/awk -f
BEGIN {
	printf "%18s    %8s %8s %8s\n", "cache", "active", "alloc", "%util";
}

{
	if ($3 != 0.0) {
		pct  = 100.0 * $2 / $3;
		frac = (10000.0 * $2 / $3) % 100;
	} else {
		pct  = 100.0;
		frac = 0.0;
	}
	active = ($2 * $4)/1024;
	alloc  = ($3 * $4)/1024;
	if ((alloc - active) < 1.0) {
		pct  = 100.0;
		frac = 0.0;
	}
	printf "%18s: %8dKB %8dKB  %3d.%-2d\n", $1, active, alloc, pct, frac;
}

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#!/bin/sh
while : ; do
	grep -v '^slabinfo' /proc/slabinfo	\
		| bloatmon			\
		| sort -n -k 4,4		\
		| head -22
	sleep 5
	echo
done