Re: [PATCH bpf-next 2/2] selftests/bpf: add loop test 5

2019-08-05 Thread Alexei Starovoitov
On Sun, Aug 04, 2019 at 05:45:23AM +, Yonghong Song wrote: > > > On 8/2/19 4:33 PM, Alexei Starovoitov wrote: > > Add a test with multiple exit conditions. > > It's not an infinite loop only when the verifier can properly track > > all math on variable 'i' through all possible ways of executi

Re: [PATCH bpf-next 2/2] selftests/bpf: add loop test 5

2019-08-03 Thread Yonghong Song
On 8/2/19 4:33 PM, Alexei Starovoitov wrote: > Add a test with multiple exit conditions. > It's not an infinite loop only when the verifier can properly track > all math on variable 'i' through all possible ways of executing this loop. Agreed with motivation of this test. > > barrier()s are ne

[PATCH bpf-next 2/2] selftests/bpf: add loop test 5

2019-08-02 Thread Alexei Starovoitov
Add a test with multiple exit conditions. It's not an infinite loop only when the verifier can properly track all math on variable 'i' through all possible ways of executing this loop. barrier()s are needed to disable llvm optimization that combines multiple branches into fewer branches. Signed-o