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From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Wed, 6 May 2020 14:56:17 -0700
Message-ID: <CAEf4BzYxTTND7T7X0dLr2CbkEvUuKtarOeoJYYROefij+qds0w@mail.gmail.com>
Subject: Re: [PATCH 1/2] lib/bpf hashmap: increase portability
To:     Ian Rogers <irogers@google.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 2:47 PM Ian Rogers <irogers@google.com> wrote:
>
> 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?

It might work. Do you mind forking https://github.com/libbpf/libbpf
and trying to execute travis CI tests with such change? It compiles
across a range of distros and arches. You might need to set up Travis
CI login, hope that's not a problem. Thanks!

>
> 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
> > >