Add kernel configs necessary for enabling traffic control's (tc) NETEM#1334
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zasgar merged 3 commits intopixie-io:mainfrom May 17, 2023
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Signed-off-by: Dom Del Nano <ddelnano@pixielabs.ai>
etep
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#ci:bpf-build-all-kernels Signed-off-by: Vihang Mehta <vihang@pixielabs.ai>
zasgar
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pixie-io#1334) Summary: Add kernel configs necessary for enabling traffic control's (tc) NETEM The goal with this change is to enable more advanced network shaping during BPF testing. For example, the recently added tcp stats source connector tracks tcp retransmissions, but we don't have a way to cause these retransmissions in order to verify that functionality works. I'd like to use the [tc-netem](https://man7.org/linux/man-pages/man8/tc-netem.8.html) functionality to inject latency into a network interface that specific gtests can listen on (thinking link local interface that specific tests can opt themselves into). Configuring that interface and providing a nice c++ interface to it will come in later changes. Busybox provides a [tc utility](https://boxmatrix.info/wiki/Property:tc_(bbcmd)), so I don't think any additional userspace tools are necessary. I will validate that the userspace component of this works once this kernel is available. If there are good ways to do this ahead of time, I'm happy to do that validation. It seems like I need to push a kernel to gcs or find a way for bazel to use a local kernel to do that. Relevant Issues: N/A Type of change: /kind test-infra Test Plan: Verified the following the ensure the kernel config applied correctly - [x] Verified compiling our oldest and newest kernel results in `net/sched/sch_netem.o` built into the kernel ``` $ make -C tools/docker .build/kernel_build/linux-build-6.1.18.tar.gz 2>&1 | grep sch_netem CC net/sched/sch_netem.o $ make -C tools/docker .build/kernel_build/linux-build-4.14.254.tar.gz 2>&1 | grep sch_netem CC net/sched/sch_netem.o ``` Signed-off-by: Dom Del Nano <ddelnano@pixielabs.ai>
ddelnano
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Feb 25, 2026
pixie-io#1334) Summary: Add kernel configs necessary for enabling traffic control's (tc) NETEM The goal with this change is to enable more advanced network shaping during BPF testing. For example, the recently added tcp stats source connector tracks tcp retransmissions, but we don't have a way to cause these retransmissions in order to verify that functionality works. I'd like to use the [tc-netem](https://man7.org/linux/man-pages/man8/tc-netem.8.html) functionality to inject latency into a network interface that specific gtests can listen on (thinking link local interface that specific tests can opt themselves into). Configuring that interface and providing a nice c++ interface to it will come in later changes. Busybox provides a [tc utility](https://boxmatrix.info/wiki/Property:tc_(bbcmd)), so I don't think any additional userspace tools are necessary. I will validate that the userspace component of this works once this kernel is available. If there are good ways to do this ahead of time, I'm happy to do that validation. It seems like I need to push a kernel to gcs or find a way for bazel to use a local kernel to do that. Relevant Issues: N/A Type of change: /kind test-infra Test Plan: Verified the following the ensure the kernel config applied correctly - [x] Verified compiling our oldest and newest kernel results in `net/sched/sch_netem.o` built into the kernel ``` $ make -C tools/docker .build/kernel_build/linux-build-6.1.18.tar.gz 2>&1 | grep sch_netem CC net/sched/sch_netem.o $ make -C tools/docker .build/kernel_build/linux-build-4.14.254.tar.gz 2>&1 | grep sch_netem CC net/sched/sch_netem.o ``` Signed-off-by: Dom Del Nano <ddelnano@pixielabs.ai>
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Summary: Add kernel configs necessary for enabling traffic control's (tc) NETEM
The goal with this change is to enable more advanced network shaping during BPF testing. For example, the recently added tcp stats source connector tracks tcp retransmissions, but we don't have a way to cause these retransmissions in order to verify that functionality works.
I'd like to use the tc-netem functionality to inject latency into a network interface that specific gtests can listen on (thinking link local interface that specific tests can opt themselves into). Configuring that interface and providing a nice c++ interface to it will come in later changes.
Busybox provides a tc utility, so I don't think any additional userspace tools are necessary. I will validate that the userspace component of this works once this kernel is available. If there are good ways to do this ahead of time, I'm happy to do that validation. It seems like I need to push a kernel to gcs or find a way for bazel to use a local kernel to do that.
Relevant Issues: N/A
Type of change: /kind test-infra
Test Plan: Verified the following the ensure the kernel config applied correctly
net/sched/sch_netem.obuilt into the kernel.configand.config.oldfile maintained the added kernel configs (P382)