Re: [PATCH] gdb.gdb/python-helper.exp: Increase timeout values

[Tom de Vries <tdevries@suse.de>]

On 9/6/26 6:01 AM, Thiago Jung Bauermann wrote:
> In the three Linux machines I tested (my x86_64 laptop and two aarch64
> servers), gdb.gdb/python-helper.exp has this timeout failure:
> 
> FAIL: gdb.gdb/python-helper.exp: pretty print type instance flags (timeout)
> 
> And the slower aarch64 server also has this one:
> 
> FAIL: gdb.gdb/python-helper.exp: start inner gdb (timeout)
> 
> Fix these failures by using timeout factors.  For the latter, a 2x factor
> is enough.  For the former, I needed 8x.  It appears that the "pretty print
> type instance flags" test is quite demanding.

I tried to see if I could reproduce this.  I ended up writing a patch ( 
https://sourceware.org/pipermail/gdb-patches/2026-September/230135.html 
) for some timeout but I have no idea whether it's the same root cause 
or not.  You may want to test it.

Assuming it's not, LGTM.

Approved-By: Tom de Vries <tdevries@suse.de>

> ---
> 
> I actually noticed these failures because I compared GDB 17.2 test
> results with GDB 18 ones. OK to also push to the branch?
> 

This makes me wonder if we're dealing with a performance regression 
here, but yeah, I suppose it's ok.

Thanks,
- Tom


>   gdb/testsuite/gdb.gdb/python-helper.exp | 40 ++++++++++++++-----------
>   1 file changed, 22 insertions(+), 18 deletions(-)
> 
> diff --git a/gdb/testsuite/gdb.gdb/python-helper.exp b/gdb/testsuite/gdb.gdb/python-helper.exp
> index d84e48166995..bcd94b2e6ae5 100644
> --- a/gdb/testsuite/gdb.gdb/python-helper.exp
> +++ b/gdb/testsuite/gdb.gdb/python-helper.exp
> @@ -91,19 +91,21 @@ proc test_python_helper {} {
>       # little clearer when trying to unpick which GDB is active.
>       gdb_test_no_output -prompt $outer_prompt_re  "set prompt (outer-gdb) " "set outer gdb prompt"
>   
> -    # Send a command to the outer GDB to continue the inner GDB.  The
> -    # stop is being detected from the inner GDB, hence the use of -i
> -    # here.
> -    gdb_test_multiple "continue" "start inner gdb" {
> -	-re "received signal SIGSEGV.* in GC_.*$outer_prompt_re" {
> -	    # Some versions of the GC used by Guile cause a SEGV
> -	    # during stack probing.  Ignore this and carry on.
> -	    send_gdb "continue\n"
> -	    exp_continue
> -	}
> -	-i "$inferior_spawn_id"
> -	-re "\r\n$gdb_prompt $" {
> -	    pass $gdb_test_name
> +    with_timeout_factor 2 {
> +	# Send a command to the outer GDB to continue the inner GDB.  The
> +	# stop is being detected from the inner GDB, hence the use of -i
> +	# here.
> +	gdb_test_multiple "continue" "start inner gdb" {
> +	    -re "received signal SIGSEGV.* in GC_.*$outer_prompt_re" {
> +		# Some versions of the GC used by Guile cause a SEGV
> +		# during stack probing.  Ignore this and carry on.
> +		send_gdb "continue\n"
> +		exp_continue
> +	    }
> +	    -i "$inferior_spawn_id"
> +	    -re "\r\n$gdb_prompt $" {
> +		pass $gdb_test_name
> +	    }
>   	}
>       }
>   
> @@ -172,11 +174,13 @@ proc test_python_helper {} {
>   		    " int_stuff = \{ bit_size = $decimal, bit_offset = $decimal \}\}"]
>       gdb_test -prompt $outer_prompt_re "print *val->m_type->main_type" $answer "pretty print type->main_type"
>   
> -    # Test printing instance flags using an artificial type.
> -    set answer [string_to_regexp {instance_flags = [VOLATILE|DATA_SPACE|ADDRESS_CLASS(3)]}]
> -    gdb_test -prompt $outer_prompt_re \
> -	"print *make_type_with_harvard_address_space (make_cv_type (0, 1, make_type_with_address_class (val->m_type, 3)), 2)" \
> -	"${answer}.*" "pretty print type instance flags"
> +    with_timeout_factor 8 {
> +	# Test printing instance flags using an artificial type.
> +	set answer [string_to_regexp {instance_flags = [VOLATILE|DATA_SPACE|ADDRESS_CLASS(3)]}]
> +	gdb_test -prompt $outer_prompt_re \
> +	    "print *make_type_with_harvard_address_space (make_cv_type (0, 1, make_type_with_address_class (val->m_type, 3)), 2)" \
> +	    "${answer}.*" "pretty print type instance flags"
> +    }
>   
>       # Send the continue to the outer GDB, which resumes the inner GDB,
>       # we then detect the prompt from the inner GDB, hence the use of