Re: [GIT PULL] liblockdep for 4.12

[Ingo Molnar <mingo@kernel.org>]

* alexander.levin@verizon.com <alexander.levin@verizon.com> wrote:

> On Fri, May 05, 2017 at 08:11:38AM +0200, Ingo Molnar wrote:
> > * alexander.levin@verizon.com <alexander.levin@verizon.com> wrote:
> > Could you please include all the patches as part of the pull request, so that 
> > individual patches can be discussed?
> 
> Sure, I'll resend.
>  
> > In particular I'm wondering about:
> > 
> > >  tools/include/linux/jhash.h                    | 125 +++++++++++++++++++++++
> > 
> > include/linux/jhash.h is 175 lines long - why not make an exact copy and keep it 
> > synchronized the way perf does it?
> 
> Including jhash() vs only jhash2() required pulling additional headers in.
> Since we don't need jhash() I preferred to drop it.
> 
> Let me know if you'd prefer to do it the other way and include everything.

How many headers would that be? We already have tools/include/../bitops.h, so we'd 
only need include/linux/unaligned/packed_struct.h, which looks straightforward and 
smallish.

( That header includes kernel.h, but we have that in tools as well, so in theory 
  it could work. )

The principle would be to 'COW-share' as much code as possible, at least for 
obvious arithmetics helpers - which hashes do appear to be.

Thanks,

	Ingo