[llvm-dev] Buildbots timing out on full builds

[Daniel Sanders via llvm-dev]

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.

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