On Fri, May 22, 2020 at 11:51 AM Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > On Thu, May 21, 2020 at 5:34 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > On Sun, May 17, 2020 at 12:57:22PM -0700, Andrii Nakryiko wrote: > > > Add 4 litmus tests for BPF ringbuf implementation, divided into two different > > > use cases. > > > > > > First, two unbounded case, one with 1 producer and another with > > > 2 producers, single consumer. All reservations are supposed to succeed. > > > > > > Second, bounded case with only 1 record allowed in ring buffer at any given > > > time. Here failures to reserve space are expected. Again, 1- and 2- producer > > > cases, single consumer, are validated. > > > > > > Just for the fun of it, I also wrote a 3-producer cases, it took *16 hours* to > > > validate, but came back successful as well. I'm not including it in this > > > patch, because it's not practical to run it. See output for all included > > > 4 cases and one 3-producer one with bounded use case. > > > > > > Each litmust test implements producer/consumer protocol for BPF ring buffer > > > implementation found in kernel/bpf/ringbuf.c. Due to limitations, all records > > > are assumed equal-sized and producer/consumer counters are incremented by 1. > > > This doesn't change the correctness of the algorithm, though. > > > > Very cool!!! > > > > However, these should go into Documentation/litmus-tests/bpf-rb or similar. > > Please take a look at Documentation/litmus-tests/ in -rcu, -tip, and > > -next, including the README file. > > > > The tools/memory-model/litmus-tests directory is for basic examples, > > not for the more complex real-world ones like these guys. ;-) > > Oh, ok, I didn't realize there are more litmus tests under > Documentation/litmus-tests... Might have saved me some time (more > examples to learn from!) when I was writing mine :) Will check those > and move everything. > Ok, so Documentation/litmus-tests is not present in bpf-next, so I guess I'll have to split this patch out and post it separately. BTW, it's not in -rcu tree either, should I post this against linux-next tree directly? > > > > Thanx, Paul > > > > [...]
