From: Stephen Hemminger <stephen@networkplumber.org>
To: Daniel Gregory <daniel.gregory@bytedance.com>
Cc: Ruifeng Wang <ruifeng.wang@arm.com>,
dev@dpdk.org, Punit Agrawal <punit.agrawal@bytedance.com>,
Liang Ma <liangma@bytedance.com>
Subject: Re: [PATCH] eal/arm: replace RTE_BUILD_BUG on non-constant
Date: Thu, 2 May 2024 14:48:26 -0700 [thread overview]
Message-ID: <20240502144826.42d7012a@hermes.local> (raw)
In-Reply-To: <20240502174420.GA3883350@ste-uk-lab-gw>
On Thu, 2 May 2024 18:44:20 +0100
Daniel Gregory <daniel.gregory@bytedance.com> wrote:
> On Thu, May 02, 2024 at 09:20:45AM -0700, Stephen Hemminger wrote:
> > Why not:
> > diff --git a/lib/eal/arm/include/rte_pause_64.h b/lib/eal/arm/include/rte_pause_64.h
> > index 5cb8b59056..81987de771 100644
> > --- a/lib/eal/arm/include/rte_pause_64.h
> > +++ b/lib/eal/arm/include/rte_pause_64.h
> > @@ -172,6 +172,8 @@ rte_wait_until_equal_32(volatile uint32_t *addr, uint32_t expected,
> > {
> > uint32_t value;
> >
> > + static_assert(__builtin_constant_p(memorder), "memory order is not a constant");
> > +
> > RTE_BUILD_BUG_ON(memorder != rte_memory_order_acquire &&
> > memorder != rte_memory_order_relaxed);
> >
> > @@ -191,6 +193,8 @@ rte_wait_until_equal_64(volatile uint64_t *addr, uint64_t expected,
> > {
> > uint64_t value;
> >
> > + static_assert(__builtin_constant_p(memorder), "memory order is not a constant");
> > +
> > RTE_BUILD_BUG_ON(memorder != rte_memory_order_acquire &&
> > memorder != rte_memory_order_relaxed);
> >
>
> What toolchain are you using? With your change I still get errors about
> the expression not being constant:
>
> In file included from ../lib/eal/arm/include/rte_pause.h:13,
> from ../lib/eal/include/generic/rte_spinlock.h:25,
> from ../lib/eal/arm/include/rte_spinlock.h:17,
> from ../lib/telemetry/telemetry.c:20:
> ../lib/eal/arm/include/rte_pause_64.h: In function ‘rte_wait_until_equal_16’:
> ../lib/eal/arm/include/rte_pause_64.h:156:23: error: expression in static assertion is not constant
> 156 | static_assert(__builtin_constant_p(memorder), "memory order is not a constant");
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> I'm cross-compiling with GCC v12.2 using the
> config/arm/arm64_armv8_linux_gcc cross-file, and enabling
> RTE_ARM_USE_WFE by uncommenting it in config/arm/meson.build and setting
> its value to true.
I don't do ARM any more, suppose could build on Raspberry Pi but havent.
There are already constant checks like this elsewhere in the file. Why not this:
diff --git a/lib/eal/arm/include/rte_pause_64.h b/lib/eal/arm/include/rte_pause_64.h
index 5cb8b59056..4f54f5dac3 100644
--- a/lib/eal/arm/include/rte_pause_64.h
+++ b/lib/eal/arm/include/rte_pause_64.h
@@ -153,6 +153,7 @@ rte_wait_until_equal_16(volatile uint16_t *addr, uint16_t expected,
{
uint16_t value;
+ RTE_BUILD_BUG_ON(!__builtin_constant_p(memorder));
RTE_BUILD_BUG_ON(memorder != rte_memory_order_acquire &&
memorder != rte_memory_order_relaxed);
@@ -172,6 +173,7 @@ rte_wait_until_equal_32(volatile uint32_t *addr, uint32_t expected,
{
uint32_t value;
+ RTE_BUILD_BUG_ON(!__builtin_constant_p(memorder));
RTE_BUILD_BUG_ON(memorder != rte_memory_order_acquire &&
memorder != rte_memory_order_relaxed);
@@ -191,6 +193,7 @@ rte_wait_until_equal_64(volatile uint64_t *addr, uint64_t expected,
{
uint64_t value;
+ RTE_BUILD_BUG_ON(!__builtin_constant_p(memorder));
RTE_BUILD_BUG_ON(memorder != rte_memory_order_acquire &&
memorder != rte_memory_order_relaxed);
next prev parent reply other threads:[~2024-05-02 21:48 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-02 14:21 Daniel Gregory
2024-05-02 16:20 ` Stephen Hemminger
2024-05-02 17:44 ` Daniel Gregory
2024-05-02 18:27 ` Stephen Hemminger
2024-05-02 21:48 ` Stephen Hemminger [this message]
2024-05-03 9:46 ` Daniel Gregory
2024-05-04 0:56 ` Stephen Hemminger
2024-05-09 11:02 ` Daniel Gregory
2024-05-03 13:32 ` David Marchand
2024-05-03 14:21 ` Daniel Gregory
2024-05-03 18:27 ` [PATCH v2] " Daniel Gregory
2024-05-03 18:30 ` Daniel Gregory
2024-05-04 0:59 ` Stephen Hemminger
2024-05-06 9:30 ` Ruifeng Wang
2024-05-11 17:00 ` Wathsala Wathawana Vithanage
2024-05-04 1:02 ` [PATCH] " Stephen Hemminger
2024-05-09 11:11 ` Daniel Gregory
2024-05-09 16:47 ` Tyler Retzlaff
2024-05-11 16:48 ` Wathsala Wathawana Vithanage
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