feat: Use fq packet scheduler when BBR is enabled #338
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BBR relies on pacing that is currently only implemented on fq[1]. While this is not mandatory since [2], research[3][4][5][6] has shown that fq is still preferable to use, not only on BBR but also as a general packet scheduler on host systems. With that in mind, we can adopt using fq as the default globally in our config instead, but since this requires further consideration, let's just set this when BBR is enabled for now. This is not set on the server kernel where using fq_codel seems to be more desirable. [1] https://man7.org/linux/man-pages/man8/tc-fq.8.html [2] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=218af599fa635b107cfe10acf3249c4dfe5e4123 [3] https://research.cec.sc.edu/files/cyberinfra/files/BBR%20-%20Fundamentals%20and%20Updates%202023-08-29.pdf [4] https://groups.google.com/g/bbr-dev/c/4jL4ropdOV8/m/zNQa-cv7AAAJ - See points 3 and last 2 sentences [5] https://groups.google.com/g/bbr-dev/c/4jL4ropdOV8/m/0-bNH-KEBgAJ [6] https://github.com/torvalds/linux/blob/master/net/ipv4/tcp_bbr.c#L55-L57 Signed-off-by: Eric Naim <[email protected]>
ptr1337
approved these changes
Nov 27, 2024
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BBR relies on pacing that is currently only implemented on fq[1]. While this is not mandatory since [2], research[3][4][5][6] has shown that fq is still preferable to use, not only on BBR but also as a general packet scheduler on host systems. With that in mind, we can adopt using fq as the default globally in our config instead, but since this requires further consideration, let's just set this when BBR is enabled for now.
This is not set on the server kernel where using fq_codel seems to be more desirable.
[1] https://man7.org/linux/man-pages/man8/tc-fq.8.html
[2] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=218af599fa635b107cfe10acf3249c4dfe5e4123
[3] https://research.cec.sc.edu/files/cyberinfra/files/BBR%20-%20Fundamentals%20and%20Updates%202023-08-29.pdf
[4] https://groups.google.com/g/bbr-dev/c/4jL4ropdOV8/m/zNQa-cv7AAAJ - See points 3 and last 2 sentences
[5] https://groups.google.com/g/bbr-dev/c/4jL4ropdOV8/m/0-bNH-KEBgAJ
[6] https://github.com/torvalds/linux/blob/master/net/ipv4/tcp_bbr.c#L55-L57