Qt Creator Valgrind Memcheck tooooo slow

MHermann

Hi,
When I am using Valgrind Memcheck in Qt Creator the application starts but is tooooo slow.
Is there a possibility to speed it up?
This is the command that it used in Qt Creator to start Valgrind Memcheck.
How can I adjust this command? Maybe it is possible to optimize the execution here?

valgrind --child-silent-after-fork=yes --xml-socket=192.168.0.142:46155 --log-socket=192.168.0.142:46075 --xml=yes --smc-check=stack --tool=memcheck --gen-suppressions=all --track-origins=yes --leak-check=summary --num-callers=30 --vgdb=yes --vgdb-error=0 /usr/lib/path/app

Kind regards

sierdzio

@MHermann said in Qt Creator Valgrind Memcheck tooooo slow:

Is there a possibility to speed it up?

Yes, stop using valgrind and use address sanitizer instead. It's built into all modern GCC and clang versions. It's faster and often more accurate than valgrind.

If you're using qmake, you can add this to your .pro:

asan {
    message("Address sanitizer: enabled. Use only in debug builds")
    CONFIG *= sanitizer sanitize_address
    QMAKE_CXXFLAGS *= "-fsanitize=address -fno-omit-frame-pointer"
    QMAKE_CFLAGS *= "-fsanitize=address -fno-omit-frame-pointer"
    QMAKE_LFLAGS *= "-fsanitize=address"
}

Then call qmake with CONFIG+=asan and rebuild your project. When you run it, asan will work and start printing all memory issues to the console.

MHermann

@sierdzio:

Okay. I tried to use address sanitizer.
But now I get the following error message:

ASan runtime does not come first in initial library list; you should either link runtime to your application or manually preload it with LD_PRELOAD.

sierdzio

Hm, never seen that message :-(

Have you used this in all of your .pro files, including the one producing the executable?

MHermann

@sierdzio:
I only have one .pro file.

I had to add this environment variable: LD_PRELOAD = /usr/lib/arm-linux-gnueabihf/libasan.so.5
Now it is working.

JoeCFD

valgrind --help to list selections and run it from command line. It is not that slow as inside qt-creator.
for example:
valgrind --leak-check=full --leak-resolution=high your app

also build your app or run your app with asan from command line. It may be faster. I use qt creator only for editing and debugging.

paulf

@sierdzio I think that you meant "sometimes more accurate".

ASan will detect stack variable bounds errors.

It won't detect any issues in libc or libstdc++/libc++ unless you have a sanitizer build of those libraries.

ASan is also only byte accurate. That means that if you use bitfields and you have a byte with a mixture of uninitialized and initialized bits then it will likely not detect an error.

paulf

@MHermann Some comments about the options used.

--tool=memcheck this is the default so you don't need it (harmless though).

--track-origins=yes this is likely to cause a substantial slowdown. I recommend not turning this on until after an error has been detected.

--num-callers=30 do you really need to record callstacks to a depth of 30?

paulf

@MHermann You aren't trying to use both Valgrind and ASan are you? They aren't compatible.

MHermann

@paulf:

Thanks for the comments about the options.

I did not try to use both together. First I tried Valgrind, then I changed to ASan.