Re: [dpdk-dev] Forcing inlining for igb_uio and kni

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Jun 11, 2019 at 11:44:01AM +0200, David Marchand wrote:
>    On Tue, Jun 11, 2019 at 11:31 AM Ilya Maximets
>    <[1]i.maximets@samsung.com> wrote:
> 
>      On 11.06.2019 11:45, David Marchand wrote:
>      > I noticed that OVS CI [1] patches the dpdk sources to force some
>      inlining parameters and get kni and igb_uio to build fine.
>      >
>      > Looking at it in dpdk, meson support dropped this.
>      > In the makefiles, I can't find a reason in the git history (we go
>      back to 1.3.0rX version).
>      >
>      > [dmarchan@dmarchan dpdk]$ git grep max-inline-insns-single
>      > kernel/linux/igb_uio/Makefile:MODULE_CFLAGS += -I$(SRCDIR) --param
>      max-inline-insns-single=100
>      > kernel/linux/kni/Makefile:MODULE_CFLAGS += -I$(SRCDIR) --param
>      max-inline-insns-single=50
>      > [dmarchan@dmarchan dpdk]$ git blame origin/master --
>      kernel/linux/igb_uio/Makefile |grep max-inline-insns-single
>      > 13dc56a6 lib/librte_eal/linuxapp/igb_uio/Makefile (Intel
>       2012-12-20 00:00:00 +0100 15) MODULE_CFLAGS += -I$(SRCDIR) --param
>      max-inline-insns-single=100
>      > [dmarchan@dmarchan dpdk]$ git blame origin/master --
>      kernel/linux/kni/Makefile |grep max-inline-insns-single
>      > 3fc5ca2f lib/librte_eal/linuxapp/kni/Makefile (Intel
>      2012-12-20 00:00:00 +0100 14) MODULE_CFLAGS += -I$(SRCDIR) --param
>      max-inline-insns-single=50
>      >
>      > Is there a valid reason to keep this?
>      > 1:
>      [2]https://github.com/openvswitch/ovs/blob/master/.travis/linux-buil
>      d.sh#L81
>      <[3]https://protect2.fireeye.com/url?k=b7de159c45b1fa79.b7df9ed3-c48
>      06461f28ecaf5&u=https://github.com/openvswitch/ovs/blob/master/.trav
>      is/linux-build.sh#L81>
>      Hi, David.
>      I don't know the reason for these in OVS travis config, But we don't
>      need to know them, actually. I have a patch to drop all the kernel
>      related stuff from the DPDK build in OVS Travis checks, just didn't
>      send it yet. Will send soon, probably.
> 
>    I had this in mind since we don't need those kmods in the CI.
>    Thanks Ilya.
>    The question on dpdk side remains open :-).
>    --
>    David Marchand

I know that previously we did have issues with the modules not compiling
due to errors about maximum levels of inlines. Whether that was because of
the compiler, or the kernel makefiles at the time, I'm not sure. The kmods
seem to build fine for me now without the parameters, and the fact that
there has never been a problem reported with building using meson either,
probably indicates that the extra compiler flags can be dropped.

/Bruce