Re: [PATCH net-next V2] ARM: net: support BPF_ALU | BPF_MOD instructions in the BPF JIT.

[Alexei Starovoitov]

On Fri, Oct 02, 2015 at 05:06:47PM +0200, Nicolas Schichan wrote:
> For ARMv7 with UDIV instruction support, generate an UDIV instruction
> followed by an MLS instruction.
> 
> For other ARM variants, generate code calling a C wrapper similar to
> the jit_udiv() function used for BPF_ALU | BPF_DIV instructions.
> 
> Some performance numbers reported by the test_bpf module (the duration
> per filter run is reported in nanoseconds, between "jitted:<x>" and
> "PASS":
> 
> ARMv7 QEMU nojit:	test_bpf: #3 DIV_MOD_KX jited:0 2196 PASS
> ARMv7 QEMU jit:		test_bpf: #3 DIV_MOD_KX jited:1 104 PASS
> ARMv5 QEMU nojit:	test_bpf: #3 DIV_MOD_KX jited:0 2176 PASS
> ARMv5 QEMU jit:		test_bpf: #3 DIV_MOD_KX jited:1 1104 PASS
> ARMv5 kirkwood nojit:	test_bpf: #3 DIV_MOD_KX jited:0 1103 PASS
> ARMv5 kirkwood jit:	test_bpf: #3 DIV_MOD_KX jited:1 311 PASS
> 
> Signed-off-by: Nicolas Schichan <nschichan@xxxxxxxxxx>

run-time check for zero is there, so looks good to me
Acked-by: Alexei Starovoitov <ast@xxxxxxxxxx>

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