On Fri, Jun 14, 2024 at 05:11:30PM GMT, Simon Horman wrote: > On Mon, Jun 03, 2024 at 08:56:38PM +0200, Adrian Moreno wrote: > > Although not explicitly documented in the psample module itself, the > > definition of PSAMPLE_ATTR_SAMPLE_RATE seems inherited from act_sample. > > > > Quoting tc-sample(8): > > "RATE of 100 will lead to an average of one sampled packet out of every > > 100 observed." > > > > With this semantics, the rates that we can express with an unsigned > > 32-bits number are very unevenly distributed and concentrated towards > > "sampling few packets". > > For example, we can express a probability of 2.32E-8% but we > > cannot express anything between 100% and 50%. > > > > For sampling applications that are capable of sampling a decent > > amount of packets, this sampling rate semantics is not very useful. > > > > Add a new flag to the uAPI that indicates that the sampling rate is > > expressed in scaled probability, this is: > > - 0 is 0% probability, no packets get sampled. > > - U32_MAX is 100% probability, all packets get sampled. > > > > Signed-off-by: Adrian Moreno <amore...@redhat.com> > > Hi Adrian, > > Would it be possible to add appropriate documentation for > rate - both the original ratio variant, and the new probability > variant - somewhere? >
Hi Simon, thanks for the suggestion. Would the uapi header be a good place for such documentation? > That aside, this looks good to me. > > ... > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
