Re: [Valgrind-users] how to generate core file on invalid reads/writes?

[Tomas V. <tv...@fu...>]

On 02/20/2018 02:08 PM, Nicolas Sauvaget wrote:
> Tomas,
> 
> Timers, threads ,"real time behaviour" of your application and GDB
> may jostle each other, so you may not be able to use it.
> 

Understood. Luckily, Postgres is single-threaded, and it does not use 
timers or realtime stuff, so that should not be a problem.

> What you can do is getting a valgrind report as usual and, from this
> report, understand where the issues are. Then you instrument your
> code using VALGRIND_PRINTF_BACKTRACE(). Of course nothing is
> automatic.
> 

Yeah, that's where I started but it's not very practical approach. The 
regression tests are executing many SQL queries on many pieces of data, 
and it's nearly impossible to pinpoint which of the queries/rows 
triggers the issue based on just the report.

But it seems the gdbserver with --vgdb-error=1 is very helpful, because 
then I can inspect the full server state and identify the exact queries 
/ rows triggering the issue.

> Hope it helps you in your investigations.
> 

Yep, is sure did. Thanks to everyone on this thread for the help so far! 
And to all the devs working on valgrind - it's such a useful tool.

regards
Tomas