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Date:   Wed, 10 Apr 2019 20:15:42 -0700
From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
To:     Olof Johansson <olof@lixom.net>
Cc:     Joel Fernandes <joelaf@google.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Qais Yousef <qais.yousef@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Manoj Rao <linux@manojrajarao.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexei Starovoitov <ast@kernel.org>,
        atish patra <atishp04@gmail.com>,
        Daniel Colascione <dancol@google.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Guenter Roeck <groeck@chromium.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Karim Yaghmour <karim.yaghmour@opersys.com>,
        Kees Cook <keescook@chromium.org>,
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        Steven Rostedt <rostedt@goodmis.org>,
        Shuah Khan <shuah@kernel.org>, Yonghong Song <yhs@fb.com>
Subject: Re: [PATCH v5 1/3] Provide in-kernel headers to make extending
 kernel easier
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On Wed, Apr 10, 2019 at 09:34:49AM -0700, Olof Johansson wrote:
> On Wed, Apr 10, 2019 at 8:51 AM Joel Fernandes <joelaf@google.com> wrote:
> >
> > On Wed, Apr 10, 2019 at 11:07 AM Olof Johansson <olof@lixom.net> wrote:
> > [snip]
> > > > > Wouldn't it be more convenient to provide it in a standardized format
> > > > > such that you won't have to take an additional step, and always have
> > > > > This is that form IMO.
...
> Compared to:
>  - Extract tarball
>  - Build and load
>  - Remove file tree from filesystem

I think there are too many assumptions in this thread in regard to what
is more convenient for user space.
I think bcc should try to avoid extracting tarball into file system.
For example libbcc can uncompress kheader.tar.xz into virtual file system
of clang front-end. It's more or less std::map<string, string>
with key=path, value=content of the file. Access to such in-memory
'files' is obviously faster than doing open/read syscalls.
bcc already uses this approach for some bcc internal 'files' that
it passes to clang during compilation.
All of /proc/kheaders.tar.xz files can be passed the same way
without extracting them into real file system.

Joel, would be great if you can share corresponding bcc patch
that takes advantage of /proc/kheaders