[RFC] Decrease default timeout for libstdc++ tests to 6 minutes

The default for the GCC testsuite is 300, i.e. 5 minutes, which is the
same as the DejaGnu default.

Libstdc++ overrides this to 600, i.e. 10 minutes.

This seems ridiculously long. If any test takes that long on modern
hardware, something is wrong. We've seen this a lot recently with
buggy tests, and waiting for them to FAIL is tedious.

I've already made libstdc++.exp respect the user's setting in
~/.dejagnurc or the global site.exp file. This means anybody testing
on slow simulators or old hardware can choose their own timeout.

I've added dg-timeout-factor to the slowest std::regex tests and have
a patch to do it for the PSTL tests, which both take far too long to
compile. That means you can choose a sensible timeout appropriate for
most tests (e.g. 60 seconds) and not get spurious failures from the
few dozen tests which are just very slow.

I'd like to change the default to 6 minutes. If that goes well, I'd
like to lower it even further.

The main benefit of this will be that buggy tests which hang will get
killed sooner, so we waste less time waiting for the inevitable
timeout.


Here's the proposed patch for completeness:

On Fri, 27 Nov 2020 at 17:13, Jonathan Wakely via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> The default for the GCC testsuite is 300, i.e. 5 minutes, which is the
> same as the DejaGnu default.
>
> Libstdc++ overrides this to 600, i.e. 10 minutes.
>
> This seems ridiculously long. If any test takes that long on modern
> hardware, something is wrong. We've seen this a lot recently with
> buggy tests, and waiting for them to FAIL is tedious.
>
> I've already made libstdc++.exp respect the user's setting in
> ~/.dejagnurc or the global site.exp file. This means anybody testing
> on slow simulators or old hardware can choose their own timeout.
>
> I've added dg-timeout-factor to the slowest std::regex tests and have
> a patch to do it for the PSTL tests, which both take far too long to
> compile. That means you can choose a sensible timeout appropriate for
> most tests (e.g. 60 seconds) and not get spurious failures from the
> few dozen tests which are just very slow.
>
> I'd like to change the default to 6 minutes. If that goes well, I'd
> like to lower it even further.
>
> The main benefit of this will be that buggy tests which hang will get
> killed sooner, so we waste less time waiting for the inevitable
> timeout.
>

I think that's a good idea, I did have problems sometimes when
many tests timed out, causing the whole 'make check' to be
killed before completion by our compute farm management system.

Thanks

Christophe

>
> Here's the proposed patch for completeness:
>
> --- a/libstdc++-v3/testsuite/lib/libstdc++.exp
> +++ b/libstdc++-v3/testsuite/lib/libstdc++.exp
> @@ -248,7 +248,7 @@ proc libstdc++_init { testfile } {
>       # Set the default timeout for v3 tests.
>       # You can override this in ~/.dejagnurc or a .exp file named by $DEJAGNU.
>       if {![info exists tool_timeout]} {
> -      set tool_timeout 600
> +      set tool_timeout 360
>       }
>
>       # Default settings.
>

On 27/11/20 21:17 +0100, Christophe Lyon via Libstdc++ wrote:
>On Fri, 27 Nov 2020 at 17:13, Jonathan Wakely via Gcc-patches
><gcc-patches@gcc.gnu.org> wrote:
>>
>> The default for the GCC testsuite is 300, i.e. 5 minutes, which is the
>> same as the DejaGnu default.
>>
>> Libstdc++ overrides this to 600, i.e. 10 minutes.
>>
>> This seems ridiculously long. If any test takes that long on modern
>> hardware, something is wrong. We've seen this a lot recently with
>> buggy tests, and waiting for them to FAIL is tedious.
>>
>> I've already made libstdc++.exp respect the user's setting in
>> ~/.dejagnurc or the global site.exp file. This means anybody testing
>> on slow simulators or old hardware can choose their own timeout.
>>
>> I've added dg-timeout-factor to the slowest std::regex tests and have
>> a patch to do it for the PSTL tests, which both take far too long to
>> compile. That means you can choose a sensible timeout appropriate for
>> most tests (e.g. 60 seconds) and not get spurious failures from the
>> few dozen tests which are just very slow.
>>
>> I'd like to change the default to 6 minutes. If that goes well, I'd
>> like to lower it even further.
>>
>> The main benefit of this will be that buggy tests which hang will get
>> killed sooner, so we waste less time waiting for the inevitable
>> timeout.
>>
>
>I think that's a good idea, I did have problems sometimes when
>many tests timed out, causing the whole 'make check' to be
>killed before completion by our compute farm management system.

Thanks for the feedback. I've pushed this patch now.

It's been tested on powercp64le-linux, x86_64-linux, aarch64-linux,
sparc-solaris and powerpc-aix. They were all fine with much lower
defaults (e.g. 120 seconds). Let's see how this goes for people
testing on older or less powerful hardware.

On Mon, 30 Nov 2020 at 15:58, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On 27/11/20 21:17 +0100, Christophe Lyon via Libstdc++ wrote:
> >On Fri, 27 Nov 2020 at 17:13, Jonathan Wakely via Gcc-patches
> ><gcc-patches@gcc.gnu.org> wrote:
> >>
> >> The default for the GCC testsuite is 300, i.e. 5 minutes, which is the
> >> same as the DejaGnu default.
> >>
> >> Libstdc++ overrides this to 600, i.e. 10 minutes.
> >>
> >> This seems ridiculously long. If any test takes that long on modern
> >> hardware, something is wrong. We've seen this a lot recently with
> >> buggy tests, and waiting for them to FAIL is tedious.
> >>
> >> I've already made libstdc++.exp respect the user's setting in
> >> ~/.dejagnurc or the global site.exp file. This means anybody testing
> >> on slow simulators or old hardware can choose their own timeout.
> >>
> >> I've added dg-timeout-factor to the slowest std::regex tests and have
> >> a patch to do it for the PSTL tests, which both take far too long to
> >> compile. That means you can choose a sensible timeout appropriate for
> >> most tests (e.g. 60 seconds) and not get spurious failures from the
> >> few dozen tests which are just very slow.
> >>
> >> I'd like to change the default to 6 minutes. If that goes well, I'd
> >> like to lower it even further.
> >>
> >> The main benefit of this will be that buggy tests which hang will get
> >> killed sooner, so we waste less time waiting for the inevitable
> >> timeout.
> >>
> >
> >I think that's a good idea, I did have problems sometimes when
> >many tests timed out, causing the whole 'make check' to be
> >killed before completion by our compute farm management system.
>
> Thanks for the feedback. I've pushed this patch now.
>
> It's been tested on powercp64le-linux, x86_64-linux, aarch64-linux,
> sparc-solaris and powerpc-aix. They were all fine with much lower
> defaults (e.g. 120 seconds). Let's see how this goes for people
> testing on older or less powerful hardware.
>

FTR, I've seen two occurrences of a random timeout:
WARNING: program timed out.
27_io/basic_istream/get/wchar_t/lwg3464.cc execution test (reason: NONE)
FAIL: 27_io/basic_istream/get/wchar_t/lwg3464.cc execution test

when testing for aarch64-none-elf with -mabi=ilp32 using Arm's
Foundation Model as simulator (an old release).

Christophe

On 01/12/20 10:45 +0100, Christophe Lyon wrote:
>On Mon, 30 Nov 2020 at 15:58, Jonathan Wakely <jwakely@redhat.com> wrote:
>>
>> On 27/11/20 21:17 +0100, Christophe Lyon via Libstdc++ wrote:
>> >On Fri, 27 Nov 2020 at 17:13, Jonathan Wakely via Gcc-patches
>> ><gcc-patches@gcc.gnu.org> wrote:
>> >>
>> >> The default for the GCC testsuite is 300, i.e. 5 minutes, which is the
>> >> same as the DejaGnu default.
>> >>
>> >> Libstdc++ overrides this to 600, i.e. 10 minutes.
>> >>
>> >> This seems ridiculously long. If any test takes that long on modern
>> >> hardware, something is wrong. We've seen this a lot recently with
>> >> buggy tests, and waiting for them to FAIL is tedious.
>> >>
>> >> I've already made libstdc++.exp respect the user's setting in
>> >> ~/.dejagnurc or the global site.exp file. This means anybody testing
>> >> on slow simulators or old hardware can choose their own timeout.
>> >>
>> >> I've added dg-timeout-factor to the slowest std::regex tests and have
>> >> a patch to do it for the PSTL tests, which both take far too long to
>> >> compile. That means you can choose a sensible timeout appropriate for
>> >> most tests (e.g. 60 seconds) and not get spurious failures from the
>> >> few dozen tests which are just very slow.
>> >>
>> >> I'd like to change the default to 6 minutes. If that goes well, I'd
>> >> like to lower it even further.
>> >>
>> >> The main benefit of this will be that buggy tests which hang will get
>> >> killed sooner, so we waste less time waiting for the inevitable
>> >> timeout.
>> >>
>> >
>> >I think that's a good idea, I did have problems sometimes when
>> >many tests timed out, causing the whole 'make check' to be
>> >killed before completion by our compute farm management system.
>>
>> Thanks for the feedback. I've pushed this patch now.
>>
>> It's been tested on powercp64le-linux, x86_64-linux, aarch64-linux,
>> sparc-solaris and powerpc-aix. They were all fine with much lower
>> defaults (e.g. 120 seconds). Let's see how this goes for people
>> testing on older or less powerful hardware.
>>
>
>FTR, I've seen two occurrences of a random timeout:
>WARNING: program timed out.
>27_io/basic_istream/get/wchar_t/lwg3464.cc execution test (reason: NONE)
>FAIL: 27_io/basic_istream/get/wchar_t/lwg3464.cc execution test
>
>when testing for aarch64-none-elf with -mabi=ilp32 using Arm's
>Foundation Model as simulator (an old release).

Yes, that test only runs for target { ! lp64 } and does quite a lot of
work. It should compile quite quickly, but takes a long time to run
compared to most tests.

I've add dg-timeout-factor to it and its narrow char counterpart.

Tested x86_64-linux, pushed to trunk.

On 01/12/20 10:52 +0000, Jonathan Wakely wrote:
>On 01/12/20 10:45 +0100, Christophe Lyon wrote:
>>On Mon, 30 Nov 2020 at 15:58, Jonathan Wakely <jwakely@redhat.com> wrote:
>>>
>>>On 27/11/20 21:17 +0100, Christophe Lyon via Libstdc++ wrote:
>>>>On Fri, 27 Nov 2020 at 17:13, Jonathan Wakely via Gcc-patches
>>>><gcc-patches@gcc.gnu.org> wrote:
>>>>>
>>>>> The default for the GCC testsuite is 300, i.e. 5 minutes, which is the
>>>>> same as the DejaGnu default.
>>>>>
>>>>> Libstdc++ overrides this to 600, i.e. 10 minutes.
>>>>>
>>>>> This seems ridiculously long. If any test takes that long on modern
>>>>> hardware, something is wrong. We've seen this a lot recently with
>>>>> buggy tests, and waiting for them to FAIL is tedious.
>>>>>
>>>>> I've already made libstdc++.exp respect the user's setting in
>>>>> ~/.dejagnurc or the global site.exp file. This means anybody testing
>>>>> on slow simulators or old hardware can choose their own timeout.
>>>>>
>>>>> I've added dg-timeout-factor to the slowest std::regex tests and have
>>>>> a patch to do it for the PSTL tests, which both take far too long to
>>>>> compile. That means you can choose a sensible timeout appropriate for
>>>>> most tests (e.g. 60 seconds) and not get spurious failures from the
>>>>> few dozen tests which are just very slow.
>>>>>
>>>>> I'd like to change the default to 6 minutes. If that goes well, I'd
>>>>> like to lower it even further.
>>>>>
>>>>> The main benefit of this will be that buggy tests which hang will get
>>>>> killed sooner, so we waste less time waiting for the inevitable
>>>>> timeout.
>>>>>
>>>>
>>>>I think that's a good idea, I did have problems sometimes when
>>>>many tests timed out, causing the whole 'make check' to be
>>>>killed before completion by our compute farm management system.
>>>
>>>Thanks for the feedback. I've pushed this patch now.
>>>
>>>It's been tested on powercp64le-linux, x86_64-linux, aarch64-linux,
>>>sparc-solaris and powerpc-aix. They were all fine with much lower
>>>defaults (e.g. 120 seconds). Let's see how this goes for people
>>>testing on older or less powerful hardware.
>>>
>>
>>FTR, I've seen two occurrences of a random timeout:
>>WARNING: program timed out.
>>27_io/basic_istream/get/wchar_t/lwg3464.cc execution test (reason: NONE)
>>FAIL: 27_io/basic_istream/get/wchar_t/lwg3464.cc execution test
>>
>>when testing for aarch64-none-elf with -mabi=ilp32 using Arm's
>>Foundation Model as simulator (an old release).
>
>Yes, that test only runs for target { ! lp64 } and does quite a lot of
>work. It should compile quite quickly, but takes a long time to run
>compared to most tests.
>
>I've add dg-timeout-factor to it and its narrow char counterpart.

Similarly for a couple more tests which do extra work on 32-bit
targets.

Tested x86_64-linux, pushed to trunk.