Re: [PATCH v10 2/5] remus: add libnl3 dependency for network buffering support

[Hongyang Yang <yanghy@cn.fujitsu.com>]

On 06/06/2014 12:18 AM, Ian Jackson wrote:
> Yang Hongyang writes ("[PATCH v10 2/5] remus: add libnl3 dependency for network buffering support"):
>> Libnl3 is required for controlling Remus network buffering.
>> This patch adds dependency on libnl3 (>= 3.2.8) to autoconf scripts.
>> Also provide ability to configure tools without libnl3 support, that
>> is without network buffering support.
>
> This patch looks broadly good to me.  I have some very minor comments
> about the details.
>
>> when there's no network buffering support,libxl__netbuffer_enabled()
>> returns 0, otherwise returns 1.
>
> The commit message should explicitly state that callers will be
> introduced in the rest of the series.
>
>> Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
>
> For a patch which changes configure.ac, it would be helpful to add a
> reminder (for the commiter) to rerun autogen.sh.  This should ideally
> appear just before the first Signed-off-by.  The committer should
> delete the note, and rerun autogen.sh, as they apply the patch.

Thanks, will add the comment.

>
>> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
>> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
>> Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
> ...
>> +# Check for libnl3 >=3.2.8. If present enable remus network buffering.
>> +PKG_CHECK_MODULES(LIBNL3, [libnl-3.0 >= 3.2.8 libnl-route-3.0 >= 3.2.8],
>> +    [libnl3_lib="y"], [libnl3_lib="n"])
>> +
>> +AS_IF([test "x$libnl3_lib" = "xn" ], [
>> +    AC_MSG_WARN([Disabling support for Remus network buffering.
>> +    Please install libnl3 libraries, command line tools and devel
>> +    headers - version 3.2.8 or higher])
>> +    AC_SUBST(remus_netbuf, [n])
>> +    ],[
>> +    AC_SUBST(LIBNL3_LIBS)
>> +    AC_SUBST(LIBNL3_CFLAGS)
>
> It might be better to put these AC_SUBSTs into the main body of
> configure.ac ?  Like this:
>
>     diff --git a/tools/configure.ac b/tools/configure.ac
>     index 38d2d05..ee36707 100644
>     --- a/tools/configure.ac
>     +++ b/tools/configure.ac
>     @@ -257,10 +257,11 @@ AS_IF([test "x$libnl3_lib" = "xn" ], [
>          headers - version 3.2.8 or higher])
>          AC_SUBST(remus_netbuf, [n])
>          ],[
>     -    AC_SUBST(LIBNL3_LIBS)
>     -    AC_SUBST(LIBNL3_CFLAGS)
>          AC_SUBST(remus_netbuf, [y])
>      ])
>
>     +AC_SUBST(LIBNL3_LIBS)
>     +AC_SUBST(LIBNL3_CFLAGS)
>     +
>      AC_OUTPUT()

yes, i'll try that, if we do these, then the following check of 
CONFIG_REMUS_NETBUF in libxl Makefile will no longer need:


  LIBXL_LIBS =
  LIBXL_LIBS = $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest) $(LDLIBS_libxenstore) 
$(LDLIBS_libblktapctl) $(PTYFUNCS_LIBS) $(LIBUUID_LIBS)
+ifeq ($(CONFIG_REMUS_NETBUF),y)
+LIBXL_LIBS += $(LIBNL3_LIBS)
+endif

  CFLAGS_LIBXL += $(CFLAGS_libxenctrl)
  CFLAGS_LIBXL += $(CFLAGS_libxenguest)
  CFLAGS_LIBXL += $(CFLAGS_libxenstore)
  CFLAGS_LIBXL += $(CFLAGS_libblktapctl)
+ifeq ($(CONFIG_REMUS_NETBUF),y)
+CFLAGS_LIBXL += $(LIBNL3_CFLAGS)
+endif
  CFLAGS_LIBXL += -Wshadow


>
> Thanks,
> Ian.
> .
>

-- 
Thanks,
Yang.