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

[Juraj Linkeš]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit at intel.com>
> Sent: Thursday, June 4, 2020 2:23 PM
> To: Juraj Linkeš <juraj.linkes at pantheon.tech>; Thomas Monjalon
> <thomas at monjalon.net>
> Cc: arybchenko at solarflare.com; dev at dpdk.org; Honnappa Nagarahalli
> <Honnappa.Nagarahalli at arm.com>
> Subject: Re: [PATCH] ethdev: fix dpdk gcc build on Arm
> 
> On 6/4/2020 11:36 AM, Juraj Linkeš wrote:
> >
> >
> >> -----Original Message-----
> >> From: Ferruh Yigit <ferruh.yigit at intel.com>
> >> Sent: Wednesday, June 3, 2020 1:41 PM
> >> To: Thomas Monjalon <thomas at monjalon.net>; Juraj Linkeš
> >> <juraj.linkes at pantheon.tech>
> >> Cc: arybchenko at solarflare.com; dev at 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?
> 

I sent an e-mail to dpdk dev a few days back asking for help where I outlined what we're doing:
We're not doing anything special, just downloading and extracting the archive, then setting CONFIG_RTE_LIBRTE_MLX5_PMD and CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC to y in config/common_base and then running make install T=arm64-armv8a-linuxapp-gcc -j. As mentioned in the subject, the build server is a Taishan ARM server.

We're doing a fresh rebuild everytime. The error doesn't happen everytime, just sometimes - it seems to be random.

We don't set RTE_SDK nor RTE_TARGET since https://doc.dpdk.org/guides/linux_gsg/build_dpdk.html#installation-of-dpdk-target-environment-using-make doesn't mention those.

I'll try Meson build a few times. How can I enable those two config options in Meson?

> 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 at pantheon.tech>
> >>>
> >>> What about #include <rte_ethdev_trace.h> ?
> >>>
> >>> Except this,
> >>> Acked-by: Thomas Monjalon <thomas at 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 at dpdk.org
> >>>
> >>>
> >>>
> >