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From:   Ian Rogers <irogers@google.com>
Date:   Wed, 6 May 2020 14:47:44 -0700
Message-ID: <CAP-5=fXUxcGZbrJMONLBasui2S=pvta7YZENEqSkenvZis58VA@mail.gmail.com>
Subject: Re: [PATCH 1/2] lib/bpf hashmap: increase portability
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andriin@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Wed, May 6, 2020 at 2:33 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Wed, May 6, 2020 at 1:54 PM Ian Rogers <irogers@google.com> wrote:
> >
> > Don't include libbpf_internal.h as it is unused and has conflicting
> > definitions, for example, with tools/perf/util/debug.h.
> > Fix a non-glibc include path.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >  tools/lib/bpf/hashmap.h | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
> > index bae8879cdf58..d5ef212a55ba 100644
> > --- a/tools/lib/bpf/hashmap.h
> > +++ b/tools/lib/bpf/hashmap.h
> > @@ -13,9 +13,8 @@
> >  #ifdef __GLIBC__
> >  #include <bits/wordsize.h>
> >  #else
> > -#include <bits/reg.h>
> > +#include <linux/bitops.h>
>
> why this change? It might be ok for libbpf built from kernel source,
> but it will break Github libbpf.

Without this change my debian based machine wasn't able to build
within the kernel tree. I see bits/wordsize.h on the machine. Perhaps
the __WORDSIZE computation could just be based on __LP64__ to remove
any #include?

Thanks,
Ian

> >  #endif
> > -#include "libbpf_internal.h"
>
> Dropping this seems ok, don't remember why I had it here in the first place.
>
> >
> >  static inline size_t hash_bits(size_t h, int bits)
> >  {
> > --
> > 2.26.2.526.g744177e7f7-goog
> >