Re: pgbench - minor fix for meta command only scripts

On Mon, Sep 4, 2017 at 1:56 PM, Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> wrote:

>
> Hello Jeff,
>
> I have fixed a bug introduced in the patch by changing && by || in the
>>>> (min_sec > 0 && maxsock != -1) condition which was inducing errors with
>>>> multi-threads & clients...
>>>>
>>>
> Since this commit (12788ae49e1933f463bc5), if I use the --rate to throttle
>> the transaction rate, it does get throttled to about the indicated speed,
>> but the pg_bench consumes the entire CPU.
>>
>>
>> At the block of code starting
>> if (min_usec > 0 && maxsock != -1)
>>
>> If maxsock == -1, then there is no sleep happening.
>>
>
> Argh, shame on me:-(
>
> I cannot find the "induced errors" I was refering to in the message...
> Sleeping is definitely needed to avoid a hard loop.
>
> Patch attached fixes it and does not seem introduce any special issue...
>
> Should probably be backpatched.
>
> Thanks for the debug!

Thanks Fabien, that works for me.

But if min_sec <= 0, do we want to do whatever it is that we already know
is over-do, before stopping to do the select? If it is safe to go through
this code path when maxsock == -1, then should we just change it to this?

if (min_usec > 0)

Cheers,

Jeff