Messages in this thread | | | Date | Wed, 16 Aug 2023 08:02:29 -0700 | From | Stephen Hemminger <> | Subject | Re: [PATCH v2 net-next 0/3] netem: use a seeded PRNG for loss and corruption events |
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On Tue, 15 Aug 2023 11:23:37 +0200 Francois Michel <francois.michel@uclouvain.be> wrote:
> From: François Michel <francois.michel@uclouvain.be> > > In order to reproduce bugs or performance evaluation of > network protocols and applications, it is useful to have > reproducible test suites and tools. This patch adds > a way to specify a PRNG seed through the > TCA_NETEM_PRNG_SEED attribute for generating netem > loss and corruption events. Initializing the qdisc > with the same seed leads to the exact same loss > and corruption patterns. If no seed is explicitly > specified, the qdisc generates a random seed using > get_random_u64(). > > This patch can be and has been tested using tc from > the following iproute2-next fork: > https://github.com/francoismichel/iproute2-next > > For instance, setting the seed 42424242 on the loopback > with a loss rate of 10% will systematically drop the 5th, > 12th and 24th packet when sending 25 packets. > > v1 -> v2: Address comments and directly use > prandom_u32_state() instead of get_random_u32() for > generating loss and corruption events. Generates a random > seed using get_random_u64() if none was provided explicitly.
For series. Acked-by: Stephen Hemminger <stephen@networkplumber.org>
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