yay! https://twitter.com/mtrantalainen/status/1592525968861990914
On Tue, Nov 15, 2022 at 6:08 AM Herbert Wolverson via LibreQoS <libreqos@lists.bufferbloat.net> wrote: > > Hey! > > Just wanted to announce that cpumap-pping is now tagged as the 1.0 release. > > The one major change from RC1 is that the xdp_pping utility no longer does > any cleaning - it just reports statistics. That makes its execution a LOT > faster, and removes a stalling issue that was showing up under heavy (5 > gbit/s+) load. > > Under the hood, each "report flow" now carries a "recycle time" and a "fresh > data" flag. They are also stored in an "LRU map" rather than a strict hash > map - so if the buffer fills up, it automatically (in kernel space) evicts > (replaces) the oldest member rather than pausing to report the event. This in > turn allows for all memory allocation to be up-front (on load), so there are > no memory allocations or reallocations within the running RTT tracking system. > > Once a "report flow" has achieved its target number of samples, it stops > collecting data. 30 seconds (by default, it's configurable) later, the flow > is "recycled" - its buffer is empties, "fresh data" is set to false, and the > recycle time bumped to "now + 30 seconds". If data arrives, "fresh data" is > set to true - and the reporting tool will show the new data. If no data > arrives, the flow ages slowly to the bottom of the list and is replaced with > no memory allocation/deallocation/reallocation. > > This has largely eliminated the occasional variance in execution time (it > never spiked above 6000 nanoseconds to begin with; but now it's consistently > under 0.0005 ms added ping time; you won't notice it). More importantly, it > completely eradicated the high-load behavior of the xdp_pping sitting and > spinning for long periods of times under high lock contention. > > -- Herbert > _______________________________________________ > LibreQoS mailing list > LibreQoS@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/libreqos -- This song goes out to all the folk that thought Stadia would work: https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz Dave Täht CEO, TekLibre, LLC _______________________________________________ LibreQoS mailing list LibreQoS@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/libreqos
