From: Jakub Kicinski Date: Fri, 18 Aug 2023 02:15:07 +0000 (-0700) Subject: Merge branch 'netem-use-a-seeded-prng-for-loss-and-corruption-events' X-Git-Tag: v6.6.7~2079^2~93 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0c2d8227ba7881306d8404a3a2ffd97ac479fc0a;p=platform%2Fkernel%2Flinux-starfive.git Merge branch 'netem-use-a-seeded-prng-for-loss-and-corruption-events' François Michel says: ==================== netem: use a seeded PRNG for loss and corruption events 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. ==================== Link: https://lore.kernel.org/r/20230815092348.1449179-1-francois.michel@uclouvain.be Signed-off-by: Jakub Kicinski --- 0c2d8227ba7881306d8404a3a2ffd97ac479fc0a