[llvm-dev] Buildbots timing out on full builds

[Daniel Sanders via llvm-dev]

Is that with -fsanitize=memory too?

I'm currently building ToT with r303258 reverted. Once that's done I'll commit the revert and start investigating fixes.

> On 22 May 2017, at 10:22, Diana Picus <diana.picus at linaro.org> wrote:
> 
> Hi Daniel,
> 
> I did your experiment on a TK1 machine (same as the bots) and for r303258 I get:
> real    18m28.882s
> user    35m37.091s
> sys     0m44.726s
> 
> and for r303259:
> real    50m52.048s
> user    88m25.473s
> sys     0m46.548s
> 
> If I can help investigate, please let me know, otherwise we can just
> try your fixes and see how they affect compilation time.
> 
> Thanks,
> Diana
> 
> On 22 May 2017 at 10:49, Daniel Sanders <daniel_l_sanders at apple.com> wrote:
>> r303341 is the re-commit of the r303259 which tripled the number of rules
>> that can be imported into GlobalISel from SelectionDAG. A compile time
>> regression is to be expected but when I looked into it I found it was ~25s
>> on my machine for the whole incremental build rather than the ~12mins you
>> are seeing. I'll take another look.
>> 
>> I'm aware of a couple easy improvements we could make to the way the
>> importer works. I was leaving them until we change it over to a state
>> machine but the most obvious is to group rules by their top-level gMIR
>> instruction. This would reduce the cost of the std::sort that handles the
>> rule priorities in generating the source file and will also make it simpler
>> for the compiler to compile it.
>> 
>> 
>> On 21 May 2017, at 11:16, Vitaly Buka <vitalybuka at google.com> wrote:
>> 
>> It must be r303341, I commented on corresponding llvm-commits thread.
>> 
>> On Fri, May 19, 2017 at 7:34 AM, Diana Picus via llvm-dev
>> <llvm-dev at lists.llvm.org> wrote:
>>> 
>>> Ok, thanks. I'll try to do a bisect next week to see if I can find it.
>>> 
>>> Cheers,
>>> Diana
>>> 
>>> On 19 May 2017 at 16:29, Daniel Sanders <daniel_l_sanders at apple.com>
>>> wrote:
>>>> 
>>>>> On 19 May 2017, at 14:54, Daniel Sanders via llvm-dev
>>>>> <llvm-dev at lists.llvm.org> wrote:
>>>>> 
>>>>> r303259 will have increased compile-time since it tripled the number of
>>>>> importable
>>>>> SelectionDAG rules but a quick measurement building the affected file:
>>>>>   ninja
>>>>> lib/Target/<Target>/CMakeFiles/LLVM<Target>CodeGen.dir/<Target>InstructionSelector.cpp.o
>>>>> for both ARM and AArch64 didn't show a significant increase. I'll check
>>>>> whether
>>>>> it made a different to linking.
>>>> 
>>>> I don't think it's r303259. Starting with a fully built r303259, then
>>>> updating to r303258 and running 'ninja' gives me:
>>>>        real    2m28.273s
>>>>        user    13m23.171s
>>>>        sys     0m47.725s
>>>> then updating to r303259 and running 'ninja' again gives me:
>>>>        real    2m19.052s
>>>>        user    13m38.802s
>>>>        sys     0m44.551s
>>>> 
>>>>> sanitizer-x86_64-linux-fast also timed out after one of my commits this
>>>>> morning.
>>>>> 
>>>>>> On 19 May 2017, at 14:14, Diana Picus <diana.picus at linaro.org> wrote:
>>>>>> 
>>>>>> Hi,
>>>>>> 
>>>>>> We've noticed that recently some of our bots (mostly
>>>>>> clang-cmake-armv7-a15 and clang-cmake-thumbv7-a15) started timing out
>>>>>> whenever someone commits a change to TableGen:
>>>>>> 
>>>>>> r303418:
>>>>>> http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/7268
>>>>>> r303346:
>>>>>> http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/7242
>>>>>> r303341:
>>>>>> http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/7239
>>>>>> r303259:
>>>>>> http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/7198
>>>>>> 
>>>>>> TableGen changes before that (I checked about 3-4 of them) don't have
>>>>>> this problem:
>>>>>> r303253:
>>>>>> http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/7197
>>>>>> 
>>>>>> That one in particular actually finishes the whole build in 635s,
>>>>>> which is only a bit over 50% of the timeout limit (1200s). So, between
>>>>>> r303253 and now, something happened that made full builds
>>>>>> significantly slower. Does anyone have any idea what that might have
>>>>>> been? Also, has anyone noticed this on other bots?
>>>>>> 
>>>>>> Thanks,
>>>>>> Diana
>>>>> 
>>>>> _______________________________________________
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>>>>> llvm-dev at lists.llvm.org
>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>> 
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>> 
>> 
>>