On Thu, Jan 12, 2017 at 6:12 AM, Savolainen, Petri (Nokia - FI/Espoo) <petri.savolai...@nokia-bell-labs.com> wrote: > This patch is now merged, although I had some doubts that it has bad impact > on performance. Here are some performance results for couple of simple, > single thread packet alloc/free test cases. No references involved, just > plain packets as before. > > Test results before and after "linux-generic: packet: implement reference > apis": > > CPU cycles per operation > before after > packet_alloc 127.8 250.9 +96 % > packet_alloc_multi 873.7 1538.8 +76 % > packet_free 31 116.8 +277 % > packet_free_multi 214.5 1369.2 +538 % > packet_alloc_free 73.4 193.7 +164 % > packet_alloc_free_multi 286.1 1228.8 +330 % > > > Huge performance degradation. Numbers are now many times worse than before or > after my optimizations. To me this shows that almost a complete rewrite (or > revert) is needed.
My guess is this is due to the atomics needed for reference counting not being properly inlined internally. I know you did similar optimizations for ticketlocks. Let me look into this and post a patch that does the same for the atomics. > > -Petri > > >> -----Original Message----- >> From: lng-odp [mailto:lng-odp-boun...@lists.linaro.org] On Behalf Of Bill >> Fischofer >> Sent: Thursday, January 05, 2017 4:56 PM >> To: lng-odp@lists.linaro.org >> Subject: [lng-odp] [API-NEXT PATCHv6 2/5] linux-generic: packet: implement >> reference apis >> >> Implement the APIs: >> - odp_packet_ref_static() >> - odp_packet_ref() >> - odp_packet_ref_pkt() >> - odp_packet_is_ref() >> - odp_packet_unshared_len() >> >> This also involves functional upgrades to the existing packet manipulation >> APIs to work with packet references as input arguments. >> >> Signed-off-by: Bill Fischofer <bill.fischo...@linaro.org> >> --- >> .../linux-generic/include/odp_packet_internal.h | 73 ++- >> platform/linux-generic/odp_packet.c | 542
