Yes: I discovered that tested performance on copper-rs a high performance OS for robotics when I run it on ext4 and what is annoying in robotics is the max latency & jitter. Especially that we allocate large slabs so this is not helping at all.
(fragmented relative to baseline)
bandwidth: 100.65 -> 94.74 MiB/s (-5.86%)
elapsed time: 339.550 -> 360.699 s (+6.23%)
mean latency: 9935.7 -> 10554.6 us (+6.23%)
p50 latency: 6715.2 -> 6838.9 us (+1.84%)
p95 latency: 19394.4 -> 20599.9 us (+6.22%)
p99 latency: 131498.2 -> 131988.3 us (+0.37%)
max latency: 183713.2 -> 624392.9 us (+239.87%)
jitter stddev: 17823.1 -> 19806.0 us (+11.13%)
jitter CV: 179.38 -> 187.65% (+4.61%)
Also check your nvme granularity with fstrim -D if you are on 4KB your nvme is so fine grain that it doesn't matter much but if it is 64KB like my main one. Ouch, those small files in the middle of the 64KB won't magically go away.
Comments
Yes: I discovered that tested performance on copper-rs a high performance OS for robotics when I run it on ext4 and what is annoying in robotics is the max latency & jitter. Especially that we allocate large slabs so this is not helping at all.
(fragmented relative to baseline) bandwidth: 100.65 -> 94.74 MiB/s (-5.86%) elapsed time: 339.550 -> 360.699 s (+6.23%) mean latency: 9935.7 -> 10554.6 us (+6.23%) p50 latency: 6715.2 -> 6838.9 us (+1.84%) p95 latency: 19394.4 -> 20599.9 us (+6.22%) p99 latency: 131498.2 -> 131988.3 us (+0.37%) max latency: 183713.2 -> 624392.9 us (+239.87%) jitter stddev: 17823.1 -> 19806.0 us (+11.13%) jitter CV: 179.38 -> 187.65% (+4.61%)
Also check your nvme granularity with fstrim -D if you are on 4KB your nvme is so fine grain that it doesn't matter much but if it is 64KB like my main one. Ouch, those small files in the middle of the 64KB won't magically go away.