Re: [dpdk-dev] [PATCH] ethdev: fix dpdk gcc build on Arm

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 6/4/2020 11:36 AM, Juraj Linkeš wrote:
> 
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>> Sent: Wednesday, June 3, 2020 1:41 PM
>> To: Thomas Monjalon <thomas@monjalon.net>; Juraj Linkeš
>> <juraj.linkes@pantheon.tech>
>> Cc: arybchenko@solarflare.com; dev@dpdk.org
>> Subject: Re: [PATCH] ethdev: fix dpdk gcc build on Arm
>>
>> On 6/3/2020 11:16 AM, Thomas Monjalon wrote:
>>> 03/06/2020 11:48, Juraj Linkeš:
>>>> Directive #include <file> in gcc implementation searches for files in
>>>> a standard list of system directories, which leads to a sporadici
>>>> build error on Taishan arm machines:
>>>> /tmp/openvpp-testing/dpdk/lib/librte_ethdev/rte_ethdev.h:4287:10:
>>>> fatal error: rte_ethdev_core.h:
>>>> No such file or directory #include <rte_ethdev_core.h>
>>>
>>> Would be interesting to know why nobody else hit such error?
>>
>>
>> I can't see why this is happening, in the 'mk/rte.lib.mk' we have following:
>>
>> "
>> install: _preinstall build _postinstall
>> build: _preinstall
>> "
>>
>> Which should cause the library header files installed before building .c files in
>> that library.
>> So when compiling 'rte_class_eth.c', the header files should be already in install
>> folder.
>>
>>
>> I can see how/why changing to "" fixes the issue but I am not sure about this fix.
>> "rte_ethdev.h" is a public header file, that applications will include it in their
>> applications. In the public library it is more proper to have other includes from
>> system folder, using format <>.
>> Again, I can't see why it is failing but I believe we should find another solution
>> for _internal_ build error.
>>
>>
>> A very simple solution can be following, but that is also not good, since it solves
>> the issue by creating a dependency to the order of the header includes:
>>  diff --git a/lib/librte_ethdev/rte_class_eth.c b/lib/librte_ethdev/rte_class_eth.c
>>  index 6338355e25..3030c49020 100644
>>  --- a/lib/librte_ethdev/rte_class_eth.c
>>  +++ b/lib/librte_ethdev/rte_class_eth.c
>>  @@ -10,8 +10,8 @@
>>   #include <rte_kvargs.h>
>>   #include <rte_log.h>
>>
>>  -#include "rte_ethdev.h"
>>   #include "rte_ethdev_core.h"
>>  +#include "rte_ethdev.h"
>>   #include "rte_ethdev_driver.h"
>>   #include "ethdev_private.h"
>>
> 
> Thomas, Ferruh, what should be the solution? I'm not an expert on this and I can't really offer anything better, but I'd like that this gets fixed.

First we need to root cause this before trying to solve it. Honnappa also said
he can reproduce this but our CI builds can't (we are talking about tens of
builds daily on various platforms), need to understand why.
Also from Makefile I can't see how this is happening, I am feeling uneasy to fix
something before figuring out how/why it is failing.

Can you please try to collect more data on when/how this happens, initial
questions I can think of:
- Can you reproduce this with meson build?
- Is it bare DPDK build, or build part of other project (I guess I saw fd.io on
the link)
- - If this is not bare DPDK build what changes has been done to build system?
- Do you see this with fresh build (new clone) or rebuild of existing clone?
- Can you confirm you have correct RTE_SDK and RTE_TARGET environment variables?
- Can you please share your build command?

Thanks,
ferruh

> 
>>>
>>>
>>>> Fix this by replacing the directive with #include "file" which
>>>> searches for files first in the directory containing the current file
>>>> and other directories only after that.
>>>>
>>>> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
>>>
>>> What about #include <rte_ethdev_trace.h> ?
>>>
>>> Except this,
>>> Acked-by: Thomas Monjalon <thomas@monjalon.net>
>>>
>>>
>>> I would change the title to be more generic (nothing specific to gcc or Arm
>> here):
>>> 	ethdev: fix local include
>>>
>>> It needs to be backported, so these lines are required:
>>> 	Fixes: 7f0a669e7b04 ("ethdev: add allocation helper for virtual drivers")
>>> 	Fixes: dcd5c8112bc3 ("ethdev: add PCI driver helpers")
>>> 	Fixes: ffc905f3b856 ("ethdev: separate driver APIs")
>>> 	Fixes: 331c447ad913 ("ethdev: separate internal structures into own
>> header")
>>> 	Cc: stable@dpdk.org
>>>
>>>
>>>
>