Re: [dpdk-dev] [PATCH v3 19/20] net/sfc: support flow action COUNT in transfer rules

[Thomas Monjalon <thomas@monjalon.net>]

02/07/2021 10:43, Andrew Rybchenko:
> On 7/1/21 4:05 PM, Andrew Rybchenko wrote:
> > On 7/1/21 3:34 PM, David Marchand wrote:
> >> On Thu, Jul 1, 2021 at 11:22 AM Andrew Rybchenko
> >> <andrew.rybchenko@oktetlabs.ru> wrote:
> >>> The build works fine for me on FC34, but it has
> >>> libatomic-11.1.1-3.fc34.x86_64 installed.
> >>
> >> I first produced the issue on my "old" FC32.
> >> Afaics, for FC33 and later, gcc now depends on libatomic and the
> >> problem won't be noticed.
> >> FC32 and before are EOL, but I then reproduced the issue on RHEL 8
> >> (and Intel CI reported it on Centos 8 too).
> > 
> > I see. Thanks for the clarification.
> > 
> >>>
> >>> I'd like to understand what we're trying to solve here.
> >>> Are we trying to make meson to report the missing library
> >>> correctly?
> >>>
> >>> If so, I think I can do simple check using cc.links()
> >>> which will fail if the library is not found. I'll
> >>> test that it works as expected if the library is not
> >>> completely installed.
> >>>
> >>
> >> I tried below diff, and it works for me.
> >> "works" as in net/sfc gets disabled without libatomic installed:
[...]
> >>  # for gcc compiles we need -latomic for 128-bit atomic ops
> >>  if cc.get_id() == 'gcc'
> >> +    code = '''#include <stdio.h>
> >> +    void main() { printf("Atomilink me.\n"); }
> >> +    '''
> >> +    if not cc.links(code, args: '-latomic', name: 'libatomic link check')
> >> +        build = false
> >> +        reason = 'missing dependency, "libatomic"'
> >> +        subdir_done()
> >> +    endif
> >>      ext_deps += cc.find_library('atomic')
> >>  endif
> > 
> > Many thanks, LGTM. I'll pick it up and add comments why
> > it is checked this way.
> > 
> 
> I've send v4 with the problem fixed. However, I'm afraid
> build test systems should be updated to have libatomic
> correctly installed. Otherwise, they do not really check
> net/sfc build.

When testing on old systems, sfc won't be tested anymore after this patchset.
On recent systems, sfc should be enabled I guess.
I don't see how to manage better, sorry.