> > > The setup where it goes wrong: > > > 1. Xeon E5-2699, HT on, turbo off, 1GB hugepage for both host and guest > > On the Haswell machine (on which I don't have BIOS access), HT is on, > > but I unplug siblings at runtime. > > I also have 1G pages on both sides, and I isolate the cores used by both > > testpmd and vCPUS. > > > > > 2. Fortville 40G > > > 3. Fedora 4.7.5-200.fc24.x86_64 > > > 4. gcc version 6.2.1 > > > 5. 16.11 RC2 for both host and guest > > > 6. PVP, testpmd macswap for both host and guest > > > > > > BTW, I do see indirect_desc gives slightly better performance for > loopback > > > in tests on other platforms, but don't know how PVP performs yet. > > Interesting, other platforms are also Haswell/Broadwell? > > Yes, but with different OS. > > If you don't have the setup I can do more detailed profiling for the > root cause next week, since my platform is the only one right now that > reporting the drop. > >
Hi Maxime, I just did some profiling and see much higher L2 miss in vhost dequeue with indirect_desc in my platform, indicates increase of memory access contention. I can keep digging further but might not be able to fix it in time due to limited bandwidth. Hope this helps. Thanks Zhihong
