Re: [PATCH 1/3] use config.h in USE_* users

[Dave Jones <davej@redhat.com>]

On Wed, Jun 05, 2013 at 03:14:33PM -0400, Vince Weaver wrote:
 > On Tue, 4 Jun 2013, Jiri Slaby wrote:
 > 
 > > Even if I apply those three, I still see:
 > > syscalls/perf_event_open.c: In function 'setup_breakpoints':
 > > syscalls/perf_event_open.c:237: error: 'struct perf_event_attr' has no
 > > member named 'bp_type'
 > 
 > you must be using an older distro, as some of these features that are 
 > missing were added to perf_event_open() in 2.6.33.
 > 
 > the perf_event_open() syscall is a bit annoying as fields get added
 > pretty regularly so it's hard to write code that's backward compatible at 
 > the API level.  
 > 
 > The authors of the "perf" tool don't care because their code is in the 
 > kernel tree and they always have an up-to-date include file.  Other users, 
 > like libpfm4, PAPI, and my various tools have just given up and carry 
 > along our own copy of perf_event.h, which makes things easier in the long run.
 > 
 > I'm not sure what the trinity policy is here.  Is it better to have a 
 > really elaborate config-type interface for this?  There's at least 5 or 6 
 > different versions you'd have to check for to catch all the changes 
 > between 2.6.32 and current.

For "we don't care about out of tree compatibility" like this, carrying our
own copy of the header sounds like probably the best option.

	Dave