Re: [PATCH 14/16] perf kvm: reuse some code of perf_kvm__timerfd_create()

[Ingo Molnar <mingo@kernel.org>]

* Ingo Molnar <mingo@kernel.org> wrote:

> * David Ahern <dsahern@gmail.com> wrote:
> 
> > On 9/12/13 6:08 AM, Ingo Molnar wrote:
> > >
> > >btw., I tried to build perf on a really old distro that has no timerfd.h,
> > >and got:
> > 
> > Right. I hit that last week or so with RHEL5 as a build server.
> > 
> > timerfd was introduced before perf so any system with perf capability 
> > will also have timerfd. So the problem is strictly building perf on an 
> > older system. [...]
> 
> I'm booting new kernels on an old system and I'm building it there.
> 
> So it's new kernel, new perf source and binary, old userspace.

Btw., this build failure is still there today:

  CC       builtin-kvm.o
builtin-kvm.c:23:25: error: sys/timerfd.h: No such file or directorycc1: warnings being treated as errors
builtin-kvm.c: In function ‘perf_kvm__timerfd_create’:
builtin-kvm.c:975: warning: implicit declaration of function ‘timerfd_create’
builtin-kvm.c:975: warning: nested extern declaration of ‘timerfd_create’
builtin-kvm.c:975: error: ‘TFD_NONBLOCK’ undeclared (first use in this function)
builtin-kvm.c:975: error: (Each undeclared identifier is reported only once
builtin-kvm.c:975: error: for each function it appears in.)
builtin-kvm.c:986: warning: implicit declaration of function ‘timerfd_settime’
builtin-kvm.c:986: warning: nested extern declaration of ‘timerfd_settime’
make[1]: *** [builtin-kvm.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [all] Error 2

So it would be nice to at least make it build somehow.

Thanks,

	Ingo