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

["Juraj Linkeš" <juraj.linkes@pantheon.tech>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Thursday, June 4, 2020 3:30 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>; Thomas Monjalon
> <thomas@monjalon.net>
> Cc: arybchenko@solarflare.com; dev@dpdk.org; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>
> Subject: Re: [PATCH] ethdev: fix dpdk gcc build on Arm
> 
> On 6/4/2020 1:55 PM, Juraj Linkeš wrote:
> >> -----Original Message-----
> >> From: Ferruh Yigit <ferruh.yigit@intel.com>
> >> Sent: Thursday, June 4, 2020 2:23 PM
> >> To: Juraj Linkeš <juraj.linkes@pantheon.tech>; Thomas Monjalon
> >> <thomas@monjalon.net>
> >> Cc: arybchenko@solarflare.com; dev@dpdk.org; Honnappa Nagarahalli
> >> <Honnappa.Nagarahalli@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@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?
> >>
> >
> > 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.
> 
> Can you please try with "V=1",
> "make install T=arm64-armv8a-linuxapp-gcc -j V=1", this will generate verbose
> output.
> 
> And _before_ lines compiling the 'rte_class_eth.c' you should see something like
> following lines, can you please check:
> "
> SYMLINK-FILE include/rte_ethdev_core.h
> 
> ln -nsf `.../buildtools/relpath.sh .../lib/librte_ethdev/rte_ethdev_core.h
> .../x86_64-native-linux-gcc/include` .../x86_64-native-linux-gcc/include
> "
> 
> Also for the failed case, after fail can you please check if
> a) '.../arm64-armv8a-linuxapp-gcc/build/lib/librte_ethdev/_preinstall' file exists
> b) '.../x86_64-native-linux-gcc/include/rte_ethdev_core.h' exists and it linked to
> correct file '../../lib/librte_ethdev/rte_ethdev_core.h'
> 

Thanks, I'll try with V=1. In the meantine, I tried a lot of meson builds and I didn't hit this, but I'll do some more testing to be sure.

> 
> >
> > 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@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
> >>>>>
> >>>>>
> >>>>>
> >>>
> >