dwc_eqos - jumbo packets up to 4088 #35
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Support jumbo packets up to 4088 bytes (MTU 4074). This means raising the receive buffer size up to 4096, but since it appears that NetAdapterCx allocates buffers at page granularity anyway, I don't think this actually costs anything. I tried to enable 9014-byte packets, but with system-managed buffering, I can't see how to specify that I want a small buffer (e.g. 2KB or 4KB) while also indicating that I might receive a large packet (e.g. 9014 bytes) -- the two sizes appear to be tied together. I think if we want 9014-byte jumbo frames, we either use 12KB receive buffers (very inefficient use of memory) or we use driver-managed receive buffers (a bit more work that I can't finish tonight). So stick with a 4088 byte limit for now.
mariobalanica
approved these changes
Jan 7, 2024
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Support jumbo packets up to 4088 bytes (MTU 4074). This means raising the receive buffer size up to 4096, but since it appears that NetAdapterCx allocates buffers at page granularity anyway, I don't think this actually costs anything.
I tried to enable 9014-byte packets, but with system-managed buffering, I can't see how to specify that I want a small buffer (e.g. 2KB or 4KB) while also indicating that I might receive a large packet (e.g. 9014 bytes) -- the two sizes appear to be tied together. I think if we want 9014-byte jumbo frames, we either use 12KB receive buffers (very inefficient use of memory) or we use driver-managed receive buffers (a bit more work that I can't finish tonight). So stick with a 4088 byte limit for now.