scripts

Shared workload scripts

Cgroup memory monitoring

memstats_log.sh samples cgroup v2 memory accounting into CSV. It accepts either the cgroup directory or its memory.stat path:

./memstats_log.sh /sys/fs/cgroup/redisbench 1 results/memstats.csv &
memstats_pid=$!

# Run the measured workload.

kill -TERM "$memstats_pid" 2>/dev/null || true
wait "$memstats_pid" 2>/dev/null || true

The process only needs read access to memory.stat; use elevated privileges only when the cgroup permissions require them. Use --once to take one sample:

./memstats_log.sh --once /sys/fs/cgroup/envoybench 1 memstats.csv

Each row starts with a nanosecond-resolution UTC timestamp and monotonic elapsed_seconds, followed by total and peak memory, swap, anonymous memory, page cache, kernel memory, slab, THP, zswap, active/inactive lists, faults, reclaim activity, workingset activity, and memory pressure/OOM events. Fields not exposed by a particular kernel are recorded as zero. Plot elapsed_seconds against memory_current_bytes, anon_bytes, page_cache_bytes, or another byte-valued column to create a memory timeline. page_cache_bytes is derived as max(file - shmem, 0) so tmpfs and shared-memory pages are excluded.

Fault, reclaim, workingset, and event fields are cumulative counters. Subtract the first sample from the last sample to measure activity during a workload phase.

Generate a self-contained Bokeh timeline from the CSV with:

python ./memstats_plot.py results/memstats.csv \
	--zram-csv results/zram.csv --output results/memory-timeline.html \
	--title "Workload memory timeline"

The effective-memory stack is (memory.current - zswap) + zswap + zram, with the first layer clamped to zero. Pass --zram-csv whenever a zram device backs swap, including during zswap runs.

There is no cgroup v2 peak counter for page cache. Compute peak and average usage from the sampled page_cache_bytes values. For virtual-machine workloads, host cgroup values describe the VM process and host-side caching; collect the guest cgroup's memory.stat for application-level page-cache accounting.