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selftets/damon: add a test for memcg_path leak
There was a memory leak bug in DAMOS sysfs memcg_path file. Add a
selftest to ensure the bug never comes back.
Link: https://lkml.kernel.org/r/20250619183608.6647-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
authored by
SeongJae Park
and committed by
Andrew Morton
dfa3cf0b
5d26b5bd
+44
+1
tools/testing/selftests/damon/Makefile
+1
tools/testing/selftests/damon/Makefile
+43
tools/testing/selftests/damon/sysfs_memcg_path_leak.sh
+43
tools/testing/selftests/damon/sysfs_memcg_path_leak.sh
···
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#!/bin/bash
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# SPDX-License-Identifier: GPL-2.0
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if [ $EUID -ne 0 ]
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then
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echo "Run as root"
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exit $ksft_skip
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fi
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damon_sysfs="/sys/kernel/mm/damon/admin"
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if [ ! -d "$damon_sysfs" ]
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then
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echo "damon sysfs not found"
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exit $ksft_skip
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fi
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# ensure filter directory
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echo 1 > "$damon_sysfs/kdamonds/nr_kdamonds"
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echo 1 > "$damon_sysfs/kdamonds/0/contexts/nr_contexts"
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echo 1 > "$damon_sysfs/kdamonds/0/contexts/0/schemes/nr_schemes"
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echo 1 > "$damon_sysfs/kdamonds/0/contexts/0/schemes/0/filters/nr_filters"
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filter_dir="$damon_sysfs/kdamonds/0/contexts/0/schemes/0/filters/0"
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before_kb=$(grep Slab /proc/meminfo | awk '{print $2}')
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# try to leak 3000 KiB
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for i in {1..102400};
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do
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echo "012345678901234567890123456789" > "$filter_dir/memcg_path"
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done
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after_kb=$(grep Slab /proc/meminfo | awk '{print $2}')
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# expect up to 1500 KiB free from other tasks memory
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expected_after_kb_max=$((before_kb + 1500))
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if [ "$after_kb" -gt "$expected_after_kb_max" ]
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then
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echo "maybe memcg_path are leaking: $before_kb -> $after_kb"
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exit 1
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else
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exit 0
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fi