core/packet.lua: Enable overflow check when allocating packets #884
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Enable a really important assertion that the packet freelist does not overflow when we allocate a new batch of packets. This should not be a performance issue: the check is on a slow-path where we are allocating a thousand new packets. This is actually very important. I found a bug that packetblaster would crash with heap corruption / segfault when you run it with more than 3 network interfaces at the same time. This is because it allocated too many packets for transmit/receive buffers and that error was not caught unless "developer debug" mode was enabled. (That problem is separately alleviated by snabbco#883 that reduces the descriptor queues from 32K packets to 2K packets each.)
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LGTM. Thank you for writing this; I think it's really important that Snabb handle these kinds of cases defensively. :-) |
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…o intel-2048-descriptors
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[YANG] Empty data type binary compilation
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Enable a really important assertion that the packet freelist does not overflow when we allocate a new batch of packets.
This should not be a performance issue: the check is on a slow-path where we are allocating a thousand new packets.
This is actually very important. I found a bug that packetblaster would crash with heap corruption / segfault when you run it with more than 3 network interfaces at the same time. This is because it allocated too many packets for transmit/receive buffers and that error was not caught unless "developer debug" mode was enabled.
(That problem is separately alleviated by #883 that reduces the descriptor queues from 32K packets to 2K packets each.)