On Thu, May 09, 2024 at 12:11:50PM +0100, Daniel Gregory wrote:
> On Fri, May 03, 2024 at 06:02:36PM -0700, Stephen Hemminger wrote:
> > On Thu, 2 May 2024 15:21:16 +0100
> > Daniel Gregory <daniel.greg...@bytedance.com> wrote:
> >
> > > The ARM implementation of rte_pause uses RTE_BUILD_BUG_ON to check
> > > memorder, which is not constant. This causes compile errors when it is
> > > enabled with RTE_ARM_USE_WFE. eg.
> > >
> > > ../lib/eal/arm/include/rte_pause_64.h: In function
> > > ‘rte_wait_until_equal_16’:
> > > ../lib/eal/include/rte_common.h:530:56: error: expression in static
> > > assertion is not constant
> > > 530 | #define RTE_BUILD_BUG_ON(condition) do {
> > > static_assert(!(condition), #condition); } while (0)
> > > |
> > > ^~~~~~~~~~~~
> > > ../lib/eal/arm/include/rte_pause_64.h:156:9: note: in expansion of macro
> > > ‘RTE_BUILD_BUG_ON’
> > > 156 | RTE_BUILD_BUG_ON(memorder != rte_memory_order_acquire &&
> > > | ^~~~~~~~~~~~~~~~
> > >
> > > This has been the case since the switch to C11 assert (537caad2). Fix
> > > the compile errors by replacing the check with an RTE_ASSERT.
> > >
> > > Signed-off-by: Daniel Gregory <daniel.greg...@bytedance.com>
> >
> > The only calls to rte_wait_until_equal_16 in upstream code
> > are in the test_bbdev_perf.c and test_timer.c. Looks like
> > these test never got fixed to use rte_memory_order instead of __ATOMIC_
> > defines.
>
> Apologies, the commit message could make it clearer, but this is also an
> issue for rte_wait_until_equal_32 and rte_wait_until_equal_64.
>
> rte_wait_until_equal_32 is used in a dozen or so lock tests with the old
> __ATOMIC_ defines, as well as rte_ring_generic_pvt.h and
> rte_ring_c11_pvt.h, where it's used with the new rte_memorder_order
> values. Correct me if I'm wrong, but shouldn't the static assertions in
> rte_stdatomic.h ensure that mixed usage doesn't cause any issues, even
> if using the older __ATOMIC_ defines isn't ideal?
this is just informational.
the static assertions are intended to make sure there is alignment
between the value produced by the rte_memory_order and __ATOMIC_ constant
expressions. so you can expect that intermixing __ATOMIC_ and rte_memory_order
should work.
the older __ATOMIC_ are still used in tests because i just haven't had
time to finish conversion. i have a series up now that makes most of the
conversions, it is waiting for review.
>
> > And there should be a CI test for ARM that enables the WFE code at least
> > to ensure it works!
>
> Yes, that could've caught this sooner.
