From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH v3 net-next] bpf/verifier: track liveness for pruning Date: Wed, 16 Aug 2017 00:12:58 +0200 Message-ID: <599371EA.20605@iogearbox.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, iovisor-dev To: Edward Cree , davem@davemloft.net, Alexei Starovoitov , Alexei Starovoitov Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 Acked-by: Daniel Borkmann