Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning

[David Miller <davem@davemloft.net>]

From: Daniel Borkmann <daniel@iogearbox.net>
Date: Wed, 16 Aug 2017 00:12:58 +0200

> On 08/15/2017 09:34 PM, Edward Cree wrote:
>> State of a register doesn't matter if it wasn't read in reaching an
>> exit;
>>   a write screens off all reads downstream of it from all
>>   explored_states
>>   upstream of it.
>> This allows us to prune many more branches; here are some processed
>> insn
>>   counts for some Cilium programs:
>> Program                  before  after
>> bpf_lb_opt_-DLB_L3.o       6515   3361
>> bpf_lb_opt_-DLB_L4.o       8976   5176
>> bpf_lb_opt_-DUNKNOWN.o     2960   1137
>> bpf_lxc_opt_-DDROP_ALL.o  95412  48537
>> bpf_lxc_opt_-DUNKNOWN.o  141706  78718
>> bpf_netdev.o              24251  17995
>> bpf_overlay.o             10999   9385
>>
>> The runtime is also improved; here are 'time' results in ms:
>> Program                  before  after
>> bpf_lb_opt_-DLB_L3.o         24      6
>> bpf_lb_opt_-DLB_L4.o         26     11
>> bpf_lb_opt_-DUNKNOWN.o       11      2
>> bpf_lxc_opt_-DDROP_ALL.o   1288    139
>> bpf_lxc_opt_-DUNKNOWN.o    1768    234
>> bpf_netdev.o                 62     31
>> bpf_overlay.o                15     13
>>
>> Signed-off-by: Edward Cree <ecree@solarflare.com>
> 
> Acked-by: Daniel Borkmann <daniel@iogearbox.net>

Applied, nice work Edward.