[teamd] Make changes to netlink calls #21346
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Increase the netlink buffer size from 983KB to 2MB, and eliminate a recvmsg syscall with the MSG_PEEK flag set to get the size of the message by instead telling libnl the maximum message size to expect. This is meant to help with performance in scale setups. Signed-off-by: Saikrishna Arcot <[email protected]>
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Why I did it
Partial fix for #19310.
On setups with many LAGs configured, if the teamd container is getting shut down, then there may be many messages sent from the kernel about LAGs/LAG members being removed. This may cause the netlink socket buffers to fill up.
NetworkManger (on the desktop side) uses 2MB socket buffers, whereas teamd is currently configured to use 960kB buffers. Additionally, because libnl doesn't know the size of each netlink message, it makes two
recvmsgsyscalls for each message: one to know the size of the message, and one to get the actual message. This can result in inefficiencies on weaker systems.Work item tracking
How I did it
Increase the size of the netlink buffers from 960kB to 2048kB. Additionally, specify the maximum size of each netlink message, so that libnl doesn't need to do a
MSG_PEEKfirst to get the actual length, allocate the buffer for it, and then get the actual message.How to verify it
Which release branch to backport (provide reason below if selected)
Tested branch (Please provide the tested image version)
Description for the changelog
Link to config_db schema for YANG module changes
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