On 8/30/22 21:17, Yu Zhao wrote: > TLDR > ==== > RAM utilization Throughput (95% CI) P99 Latency (95% CI) > ---------------------------------------------------------- > ~90% NS NS > ~110% +[12, 16]% -[20, 22]% I'll give you points for thinking out of the box on this one. This is a piece of hardware where both latency and bandwidth theoretically matter. I've got a slightly older but similar piece of Ubiquiti hardware with 512MB of RAM. It doesn't run OpenWRT, fwiw. Maybe my firmware is a bit outdated. *But*, most of the heavy lifting for packet flow on these systems is done in hardware. They have some hardware acceleration to be able to _route_ at gigabit speeds, so they're probably not quite as sensitive to software hiccups as lower-end routers. That said, my system at least does not typically have *any* memory pressure. Right now, it hasn't even filled free memory with page cache and it's been up for over a month: # cat /proc/meminfo MemTotal: 491552 kB MemFree: 160188 kB MemAvailable: 373088 kB Cached: 151004 kB I think a better tl;dr would be: MGLRU doesn't help much or cause any regressions on this hardware. Under (atypical) synthetic memory pressure, MGLRU did show some modest but measurable throughput and latency benefits. In other words, this provides more of a data point that MGLRU doesn't hurt medium-ish sized embedded systems. I think you could make an even stronger case with even smaller hardware or something that actually sees memory pressure on a regular basis in the wild.
