On Thu, Nov 7, 2024, at 6:12 AM, Peter Zijlstra wrote:
> On Fri, Nov 08, 2024 at 12:04:32AM +1100, Stephen Rothwell wrote:
>> Hi Peter,
>>
>> On Thu, 7 Nov 2024 11:34:14 +0100 Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>> >
>> > On Thu, Nov 07, 2024 at 06:24:11PM +1100, Stephen Rothwell wrote:
>> > So I can't get RUST=y, even though make rustavailable is happy.
>> >
>> > make LLVM=-19 allmodconfig does not get me RUST=y
>> >
>> > I started out with tip/master, tried adding rust-next, then kbuild-next
>> > gave up and tried next/master. Nada.
>>
>> Just on Linus' tree allmodconfig gives me:
>>
>> $ grep RUST .config
>> CONFIG_RUSTC_VERSION=108100
>> CONFIG_RUST_IS_AVAILABLE=y
>> CONFIG_RUSTC_LLVM_VERSION=180108
>> CONFIG_RUST=y
>> CONFIG_RUSTC_VERSION_TEXT="rustc 1.81.0"
>> CONFIG_HAVE_RUST=y
>> CONFIG_RUST_FW_LOADER_ABSTRACTIONS=y
>> CONFIG_BLK_DEV_RUST_NULL=m
>> CONFIG_RADIO_TRUST=m
>> CONFIG_HID_THRUSTMASTER=m
>> CONFIG_THRUSTMASTER_FF=y
>> CONFIG_TRUSTED_KEYS=m
>> CONFIG_HAVE_TRUSTED_KEYS=y
>> CONFIG_TRUSTED_KEYS_TPM=y
>> CONFIG_TRUSTED_KEYS_TEE=y
>> CONFIG_TRUSTED_KEYS_CAAM=y
>> CONFIG_INTEGRITY_TRUSTED_KEYRING=y
>> CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT=y
>> CONFIG_SYSTEM_TRUSTED_KEYRING=y
>> CONFIG_SYSTEM_TRUSTED_KEYS=""
>> CONFIG_SECONDARY_TRUSTED_KEYRING=y
>> CONFIG_SECONDARY_TRUSTED_KEYRING_SIGNED_BY_BUILTIN=y
>> CONFIG_SAMPLES_RUST=y
>> CONFIG_SAMPLE_RUST_MINIMAL=m
>> CONFIG_SAMPLE_RUST_PRINT=m
>> CONFIG_SAMPLE_RUST_HOSTPROGS=y
>> CONFIG_RUST_DEBUG_ASSERTIONS=y
>> CONFIG_RUST_OVERFLOW_CHECKS=y
>> CONFIG_RUST_BUILD_ASSERT_ALLOW=y
>>
>> $ rustc --version
>> rustc 1.81.0
>
> Yeah, I'm not sure what's going on. I occasionally get rust stuff, but
> mostly when I try allyesconfig. Weirdness.
>
>> > Anyway, I think the above needs something like this:
>> >
>> > ---
>> > diff --git a/rust/helpers/spinlock.c b/rust/helpers/spinlock.c
>> > index b7b0945e8b3c..5804a6062eb1 100644
>> > --- a/rust/helpers/spinlock.c
>> > +++ b/rust/helpers/spinlock.c
>> > @@ -5,11 +5,16 @@
>> > void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
>> > struct lock_class_key *key)
>> > {
>> > +#ifndef CONFIG_PREEMPT_RT
>> > #ifdef CONFIG_DEBUG_SPINLOCK
>> > __raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG);
>> > #else
>> > spin_lock_init(lock);
>> > #endif
>> > +#else
>> > + rt_mutex_base_init(&lock->lock);
>> > + __rt_spin_lock_init(lock, name, key, false);
>> > +#endif
>> > }
>> >
>> > void rust_helper_spin_lock(spinlock_t *lock)
>>
>> I will try to remember to add that to the tip tree merge tomorrow.
>
> Boqun, could you test the above and make it happen?
>
FYI, Eder is already working on this:
https://lore.kernel.org/rust-for-linux/20241106211215.2005909-1-ezulian@xxxxxxxxxx/
Eder, could you Cc locking for the next version?
Regards,
Boqun
>> > > Without the revert CONFIG_PREEMPT_RT=y, after the revert it is not set
>> > > and spinlock_check is only defined for !defined(CONFIG_PREEMPT_RT).
>> >
>> > Right, that moved PREEMPT_RT out of the preemption choice. Now I'm not
>> > sure we want it =y for all{yes,mod}config. Is the below the right
>> > incantation to avoid this?
>> >
>> > ---
>> > diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
>> > index 7c1b29a3a491..54ea59ff8fbe 100644
>> > --- a/kernel/Kconfig.preempt
>> > +++ b/kernel/Kconfig.preempt
>> > @@ -88,7 +88,7 @@ endchoice
>> >
>> > config PREEMPT_RT
>> > bool "Fully Preemptible Kernel (Real-Time)"
>> > - depends on EXPERT && ARCH_SUPPORTS_RT
>> > + depends on EXPERT && ARCH_SUPPORTS_RT && !COMPILE_TEST
>> > select PREEMPTION
>> > help
>> > This option turns the kernel into a real-time kernel by replacing
>>
>> Yeah, that will do it.
>
> OK, I'll write it up and stick that in tip/sched/core along with them
> patches that's causing the grief :-)
>
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