Update to Network Channel count calculation in test case 'verify_vmbus_devices_channels' #3644
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| # 2.1 Get expected channel count of each netvsc is min (num of vcpu, 8). | ||
| expected_network_channel_count = ( | ||
| node.tools[Ethtool].get_device_channels_info("eth0", True) |
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it is possible that case will change the combined channel count
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I think it is the actual value, not the expected value.
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I think it is the actual value, not the expected value.
Agree, the value should be calculated, instead of getting from the system. This test case is to verify if the count of channel is the same as designed.
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Thanks for the review team. If the logic for channel calculation is updated and the said patch is available only in certain distros - it would cause the test to fail in certain cases and to succeed in others, thus creating a discrepancy. The current patch is available in SLES and Upstream but not in other distros. How can we alter the test cases to handle different logics for different situations?
Also, to avoid such a situation, wouldn't it be helpful to use a tool which refers the relevant channel calculation code at the Kernel level?
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Can it be differentiated by kernel version?
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We can do that for a short-term solution but as the patch is backported, we would need to update the kernel version for the test case.
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We can do that for a short-term solution but as the patch is backported, we would need to update the kernel version for the test case.
If the patch is backported, all newer version can use the new algorithm. So, the test cases can work with both old and newer versions.
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Thanks for the inputs @squirrelsc . Started an internal thread on this to get inputs from the Kernel team as well.
At present the network channel count calculation in the test case 'verify_vmbus_devices_channels' is based on the number of vCPUs and has a cap value of 8 - which might get updated, like in the following patch: [PATCH v4] net: netvsc: Update default VMBus channels
This patch is currently available in Upstream but not all downstream distros. Hence it is better to get the expected count using ethtool which would be dependent on the files updated in the patch above and help avoid discrepancies while testing different scenarios.