Re: [PATCH] gdb.base/siginfo-thread.exp: Increase timeout for 'gcore' command

[Wei-min Pan <weimin.pan@oracle.com>]

Pedro Alves wrote:
> On 03/16/2017 07:10 PM, Wei-min Pan wrote:
>
>   
>>> You mean that by hand it went faster than that?
>>> So what is GDB doing differently when run via make check
>>> that makes it slower than running by hand?
>>>   
>>>       
>> Yes, but not by much faster:
>>
>> % cat in
>> run
>> gcore tmp.gcore
>> quit
>>
>> % time my_gdb siginfo-thread -x in
>> ...
>> real    0m13.327s
>> user    0m3.504s
>> sys     0m7.572s
>>     
>
> Either I'm missing something, or that was _slower_ than then
> number you shown of running via the testsuite, not faster...
>   

Sorry, you didn't miss anything. I misspoke :)
> So WDT is GDB doing that takes that long?  Is that writing
> the core to a slow NFS mount or something?
>
> Here that takes:
>
>  real    0m0.120s
>  user    0m0.090s
>  sys     0m0.033s
>
> and this is not a state-of-the-art machine.
>
> Can you guess the next question?
>
> Pick any other core test in the testsuite, do the
> same and compare the numbers.
>
> And if they're different, the next question would
> then be, "what's different in this test, why's
> it slower?".
>   
OK, just tried a different test which is similar to siginfo-thread:

% time make check TESTS="*/siginfo-obj.exp"
...
real    0m1.282s
user    0m0.736s
sys     0m0.400s

Looks like the slowness had something to do with the pthread libs.
Will investigate. Thanks.
> If they're similar, then, well, the same question.  :-)
>
> Thanks,
> Pedro Alves
>
>