Re: [PATCH 1/5] selftests: Add futex functional tests

On 5/12/15, 1:05 PM, "Cyril Hrubis" [off-list ref] wrote:

Hi!

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I'm happy to do that, but I would like to make sure I'm doing the

right

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thing.

The right thing here is to add -pthread to CFLAGS which sets both flags
for preprocessor and linker (see man gcc).

Hi Cyril,

Thanks. I read that, and mentioned it, but my concern with -pthread in
the
CFLAGS and LDFLAGS is that it is a non-standard compiler flag. I
understand we have a number of gcc-isms in our build - but do we want to
add more?

I'm also struggling to find any kind of prescribed documentation on this
beyond the short blurb in the gcc man page which describes what this
option does, but not when to use it. I'll need something concrete to
justify changes to testcase Makefiles to Shuah.

Sorry to mislead you with the pointing at gcc man page.

It is a Linux standard. Have a look at pthreads manual page:
http://man7.org/linux/man-pages/man7/pthreads.7.html

"On Linux, programs that use the Pthreads API should be compiled using
cc -pthread."

Or any pthread_foo() manual page that starts with:

"Compile and link with -pthread."

The portable way i.e. POSIX would be getting compiler flags with getconf
but as this is a Linux kernel testsuite I would not bother with that.
Hmm, and it looks like this is not implemented on Linux anyway.

Thanks Cyril, that's perfect.

I'll roll my latest example patch adding -pthread to LDFLAGS and CFLAGS
into the initial patch and resubmit the patch series as v4.

Thanks all.

-- 
Darren Hart
Intel Open Source Technology Center