Reply-To: shuah@kernel.org
Subject: Re: [PATCH] selftests/bpf: Make bpf_util work on uniprocessor systems
To: Daniel Borkmann <daniel@iogearbox.net>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        Thomas Meyer <thomas@m3y3r.de>
Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Shuah Khan <shuah@kernel.org>, Shuah Khan <shuahkh@osg.samsung.com>
References: <20170908111923.27434-1-thomas@m3y3r.de>
 <20170908230155.esge2mctk5d5g7gb@ast-mbp> <59B32231.9090406@iogearbox.net>
From: Shuah Khan <shuah@kernel.org>
Message-ID: <ed20875b-7a01-fbc8-e8d1-3929ba35c8ac@kernel.org>
Date: Thu, 14 Sep 2017 09:01:19 -0600
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On 09/08/2017 05:05 PM, Daniel Borkmann wrote:
> On 09/09/2017 01:01 AM, Alexei Starovoitov wrote:
>> On Fri, Sep 08, 2017 at 01:19:23PM +0200, Thomas Meyer wrote:
>>> The current implementation fails to work on uniprocessor systems.
>>> Fix the parser to also handle the uniprocessor case.
>>>
>>> Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
>>
>> Thanks for the fix. lgtm
>> Acked-by: Alexei Starovoitov <ast@kernel.org>
> 
> Looks good from here as well:
> 
> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
> 
>> This time it's ok to go via selftest tree, but next time please use net-next/net
>> to avoid conflicts.
> 
> +1
> 
>> Thanks

Thank you. I will get this into 4.14-rc2 or rc3.

thanks,
-- Shuah
>>
>>> ---
>>>   tools/testing/selftests/bpf/bpf_util.h | 17 +++++++++--------
>>>   1 file changed, 9 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h
>>> index 20ecbaa0d85d..6c53a8906eff 100644
>>> --- a/tools/testing/selftests/bpf/bpf_util.h
>>> +++ b/tools/testing/selftests/bpf/bpf_util.h
>>> @@ -12,6 +12,7 @@ static inline unsigned int bpf_num_possible_cpus(void)
>>>       unsigned int start, end, possible_cpus = 0;
>>>       char buff[128];
>>>       FILE *fp;
>>> +    int n;
>>>
>>>       fp = fopen(fcpu, "r");
>>>       if (!fp) {
>>> @@ -20,17 +21,17 @@ static inline unsigned int bpf_num_possible_cpus(void)
>>>       }
>>>
>>>       while (fgets(buff, sizeof(buff), fp)) {
>>> -        if (sscanf(buff, "%u-%u", &start, &end) == 2) {
>>> -            possible_cpus = start == 0 ? end + 1 : 0;
>>> -            break;
>>> +        n = sscanf(buff, "%u-%u", &start, &end);
>>> +        if (n == 0) {
>>> +            printf("Failed to retrieve # possible CPUs!\n");
>>> +            exit(1);
>>> +        } else if (n == 1) {
>>> +            end = start;
>>>           }
>>> +        possible_cpus = start == 0 ? end + 1 : 0;
>>> +        break;
>>>       }
>>> -
>>>       fclose(fp);
>>> -    if (!possible_cpus) {
>>> -        printf("Failed to retrieve # possible CPUs!\n");
>>> -        exit(1);
>>> -    }
>>>
>>>       return possible_cpus;
>>>   }
>>> -- 
>>> 2.11.0
>>>
> 
> 
>