Wireshark · Wireshark-dev: [Wireshark-dev] TCP reassembly slow

[Simon Barber <simon.barber@xxxxxxxxxx>]

When loading a large file (0.5M packets) with a large single TCP stream in it, wireshark gets very slow. I did some profiling and found 90% of the CPU time was spent in epan/reassemble.c LINK_FRAG() - scanning through a long singly linked list and adding to the end of it.

As a work around I disabled 'allow subdissector to reassemble TCP streams' in the TCP protocol preferences. This makes loading this file much faster.

Simon