Good day everyone, While working on IP packet defragmenting I had to enlarge mempool size. I did this to provide large enough time window for assembling a fragment sequence. Unfortunately, I got a performance regression: if I enlarge mempool size from 2**12 to 2**20 MBufs, packet performance for not fragmented packets drops from ~8.5mpps to ~5.5mpps for single core. I made only a single measure, so the data are noisy, but the trend is evident: SIZE 4096 - 8.47mpps SIZE 8192 - 8.26mpps SIZE 16384 - 8.29mpps SIZE 32768 - 8.31mpps SIZE 65536 - 8.12mpps SIZE 131072 - 7.93mpps SIZE 262144 - 6.22mpps SIZE 524288 - 5.72mpps SIZE 1048576 - 5.63mpps
And I need even larger sizes. I want to ask for an advice, how best to tackle this? One way I'm thinking about is to make two mempools, one large for fragments (we may accumulate a big number of them) and one small for full packets, we just forward them burst by burst. Is it possible to configure RSS to distribute packets between queues according to this scheme? Perhaps, there are better ways? Thanks, Dmitry
