Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning
From: David Miller
Date: Tue Aug 15 2017 - 19:32:53 EST
From: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
>
> Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Applied, nice work Edward.