> It looks like that in our environment increasing the mempool reduce the > capture performance, any suggestion on what I might look at to > troubleshoot the problem? Apparently we can't go beyond 4GiB mempool > without performance penalties. > (Please note that 1GiB hugepage are configured to serve all the require > additional memory.)
I'd bet it on page walks because of TLB misses: if I am not mistaken, on Intel you only have 4 TLB entries for 1GB hugepages, and prior to Skylake you have no victim cache. So, as soon as you use more than 4 x 1GB hugepages, you'll start triggering page walks because all your pages do no longer fit in the TLB. You should be able to check that with 'perf stat -e dTLB-loads,dTLB-load-misses,dTLB-stores,dTLB-store-misses -a -I1000' or similar. Best ben
