Open fklassen opened 5 years ago
You need to increase /sys/module/netmap/parameters/buf_size
.
Yes, the defauit buffer size is 2048. You can either increase that (no change needed in the app, but possibly wasteful) or support NS_MOREFRAG
in tcpreplay
. Basically, you need to use several consecutive slots for a single message and set NS_MOREFRAG
in the slot flags of all but the last slot.
I am having Tcpreplay crashes when I increase the buffer size dynamically. Does the value have to be a power of two? I am attempting to accept 9018 frames. I'm not sure if I have to alter Tcpreplay source code to make this work.
or support
NS_MOREFRAG
intcpreplay
. Basically, you need to use several consecutive slots for a single message and setNS_MOREFRAG
in the slot flags of all b
I'll add a ticket to add that flag. Question: Does the flag work dynamicallay, e.g. if a 1500 byte packet comes in, will it only take one 2048 byte buffer?
The buffer size can be any value between 64 and 65536. it doesn't need to be a power of 2, but the number you enter may rounded to a multiple of a cacheline (you should see a message in the logs). The new value is not used while there are netmap applications still running.
Does the flag work dynamicallay, e.g. if a 1500 byte packet comes in, will it only take one 2048 byte buffer?
it is a per-slot flag. If you have a packet that fits a single slot, you simply don't set the flag. If you have a packet that needs 4 slots, you set the flag in the first three.
it is a per-slot flag. If you have a packet that fits a single slot, you simply don't set the flag. If you have a packet that needs 4 slots, you set the flag in the first three.
That makes sense. Thanks for clarifying. Opened appneta/tcpreplay:#534 to track this issue.
I'm having the following issue when I attempt to replay packets > 1500 bytes on 9000 MTU interface (Linux) with tcpreplay/netmap.
As far as I can tell, this is coming from this debug macro defined as 1.
Is this correct? Or is there something I have to do to TX on interfaces with MTU > 1500.
The overall effect is that performance is very poor, and logs are filling up.