On 27.11.2019 8:38, Yanqin Wei (Arm Technology China) wrote: > Hi Ilya, > > No, we didn't test this patch based on OVS-AF_XDP, but made a black build to > enable this in OVS-DPDK and test it. > Currently DPDK-AF_XDP has been tested in latest kernel (not released). So I > think OVS-AF_XDP is close to be supported for aarch64. > > Furthermore, I found a document about userspace-only mode of Open vSwitch > without DPDK. > http://docs.openvswitch.org/en/latest/intro/install/userspace/#using-the-userspace-datapath-with-ovs-vswitchd > So it seems userspace datapath should be decoupled with networking IO, users > can even customize this. Does it means we need implement all used DPDK API > inside OVS?
Userspace datapath in OVS doesn't depend on DPDK. DPDK only provides a few port types (dpdk, dpdkvhostuser, etc.). It's fully functional by itself. For example you may use it to forward packets with OVS-native afxdp ports: http://docs.openvswitch.org/en/latest/intro/install/afxdp/ Best regards, Ilya Maximets. > > Best Regards, > Wei Yanqin > > >> -----Original Message----- >> From: dev <ovs-dev-boun...@openvswitch.org> On Behalf Of Ilya Maximets >> Sent: Tuesday, November 26, 2019 11:38 PM >> To: Malvika Gupta <malvika.gu...@arm.com>; d...@openvswitch.org >> Cc: nd <n...@arm.com>; Honnappa Nagarahalli >> <honnappa.nagaraha...@arm.com> >> Subject: Re: [ovs-dev] [PATCH] dpif-netdev-perf: aarch64 support for accurate >> timing update of TSC cycle counter >> >> On 13.11.2019 18:01, Malvika Gupta wrote: >>> The accurate timing implementation in this patch gets the wall clock >>> counter via >>> cntvct_el0 register access. This call is portable to all aarch64 >>> architectures and has been verified on an 64-bit arm server. >>> >>> Suggested-by: Yanqin Wei <yanqin....@arm.com> >>> Signed-off-by: Malvika Gupta <malvika.gu...@arm.com> >>> --- >> >> Thanks for the patch! >> >> Are you trying to use AF_XDP on aarch64? Asking because it's the only real >> scenario where this patch can be useful. >> >> For the patch subject, I'd suggest to shorten it a little. >> 'timing', 'TSC' and 'cycle counter' are kind of synonyms here and doesn't >> make >> the sentence any clear. Suggesting something like this: >> "dpif-netdev-perf: Accurate cycle counter update on aarch64." >> >> What do you think? >> >> One more comment inline. >> >>> lib/dpif-netdev-perf.h | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/lib/dpif-netdev-perf.h b/lib/dpif-netdev-perf.h index >>> ce369375b..4ea7cc355 100644 >>> --- a/lib/dpif-netdev-perf.h >>> +++ b/lib/dpif-netdev-perf.h >>> @@ -220,6 +220,11 @@ cycles_counter_update(struct pmd_perf_stats *s) >>> asm volatile("rdtsc" : "=a" (l), "=d" (h)); >>> >>> return s->last_tsc = ((uint64_t) h << 32) | l; >>> +#elif !defined(_MSC_VER) && defined(__aarch64__) >>> + uint64_t tsc; >>> + asm volatile("mrs %0, cntvct_el0" : "=r" (tsc)); >>> + >>> + return s->last_tsc = tsc; >> >> I think we could drop the 'tsc' local variable here and write directly to s- >>> last_tsc. Less number of variables and operations. >> >> Best regards, Ilya Maximets. >> _______________________________________________ >> dev mailing list >> d...@openvswitch.org >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
