2024-01-15 20:20:16

by Leonardo Bras

[permalink] [raw]
Subject: [PATCH v1 1/1] spinlock: Fix failing build for PREEMPT_RT

Since 1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
spinlock.h") build fails for PREEMPT_RT, since there is no definition
available of either spin_needbreak() and rwlock_needbreak().

Since it was moved on the mentioned commit, it was placed inside a
!PREEMPT_RT part of the code, making it out of reach for an RT kernel.

Fix this by moving code it a few lines down so it can be reached by an
RT build, where it can also make use of the *_is_contended() definition
added by the spinlock_rt.h.

Fixes: d1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
spinlock.h")
Signed-off-by: Leonardo Bras <[email protected]>
---
include/linux/spinlock.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index eaac8b0da25b8..3fcd20de6ca88 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -449,6 +449,12 @@ static __always_inline int spin_is_contended(spinlock_t *lock)
return raw_spin_is_contended(&lock->rlock);
}

+#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
+
+#else /* !CONFIG_PREEMPT_RT */
+# include <linux/spinlock_rt.h>
+#endif /* CONFIG_PREEMPT_RT */
+
/*
* Does a critical section need to be broken due to another
* task waiting?: (technically does not depend on CONFIG_PREEMPTION,
@@ -480,12 +486,6 @@ static inline int rwlock_needbreak(rwlock_t *lock)
#endif
}

-#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
-
-#else /* !CONFIG_PREEMPT_RT */
-# include <linux/spinlock_rt.h>
-#endif /* CONFIG_PREEMPT_RT */
-
/*
* Pull the atomic_t declaration:
* (asm-mips/atomic.h needs above definitions)
--
2.43.0



2024-01-15 21:54:41

by Kent Overstreet

[permalink] [raw]
Subject: Re: [PATCH v1 1/1] spinlock: Fix failing build for PREEMPT_RT

On Mon, Jan 15, 2024 at 05:19:34PM -0300, Leonardo Bras wrote:
> Since 1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
> spinlock.h") build fails for PREEMPT_RT, since there is no definition
> available of either spin_needbreak() and rwlock_needbreak().
>
> Since it was moved on the mentioned commit, it was placed inside a
> !PREEMPT_RT part of the code, making it out of reach for an RT kernel.
>
> Fix this by moving code it a few lines down so it can be reached by an
> RT build, where it can also make use of the *_is_contended() definition
> added by the spinlock_rt.h.
>
> Fixes: d1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
> spinlock.h")
> Signed-off-by: Leonardo Bras <[email protected]>

I've picked this up - thanks!

2024-01-16 04:02:27

by Leonardo Bras

[permalink] [raw]
Subject: Re: [PATCH v1 1/1] spinlock: Fix failing build for PREEMPT_RT

On Mon, Jan 15, 2024 at 04:54:14PM -0500, Kent Overstreet wrote:
> On Mon, Jan 15, 2024 at 05:19:34PM -0300, Leonardo Bras wrote:
> > Since 1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
> > spinlock.h") build fails for PREEMPT_RT, since there is no definition
> > available of either spin_needbreak() and rwlock_needbreak().
> >
> > Since it was moved on the mentioned commit, it was placed inside a
> > !PREEMPT_RT part of the code, making it out of reach for an RT kernel.
> >
> > Fix this by moving code it a few lines down so it can be reached by an
> > RT build, where it can also make use of the *_is_contended() definition
> > added by the spinlock_rt.h.
> >
> > Fixes: d1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
> > spinlock.h")
> > Signed-off-by: Leonardo Bras <[email protected]>
>
> I've picked this up - thanks!
>

Awesome! Thanks!

Leo


2024-01-16 07:38:45

by Leonardo Bras

[permalink] [raw]
Subject: Re: [PATCH v1 1/1] spinlock: Fix failing build for PREEMPT_RT

On Tue, Jan 16, 2024 at 04:32:32AM -0300, Leonardo Bras wrote:
> Since 1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
> spinlock.h") build fails for PREEMPT_RT, since there is no definition
> available of either spin_needbreak() and rwlock_needbreak().
>
> Since it was moved on the mentioned commit, it was placed inside a
> !PREEMPT_RT part of the code, making it out of reach for an RT kernel.
>
> Fix this by moving code it a few lines down so it can be reached by an
> RT build, where it can also make use of the *_is_contended() definition
> added by the spinlock_rt.h.
>
> Fixes: d1d71b30e1f85 ("sched.h: Move (spin|rwlock)_needbreak() to
> spinlock.h")
> Signed-off-by: Leonardo Bras <[email protected]>
> ---
> include/linux/spinlock.h | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
> index eaac8b0da25b8..3fcd20de6ca88 100644
> --- a/include/linux/spinlock.h
> +++ b/include/linux/spinlock.h
> @@ -449,6 +449,12 @@ static __always_inline int spin_is_contended(spinlock_t *lock)
> return raw_spin_is_contended(&lock->rlock);
> }
>
> +#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
> +
> +#else /* !CONFIG_PREEMPT_RT */
> +# include <linux/spinlock_rt.h>
> +#endif /* CONFIG_PREEMPT_RT */
> +
> /*
> * Does a critical section need to be broken due to another
> * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
> @@ -480,12 +486,6 @@ static inline int rwlock_needbreak(rwlock_t *lock)
> #endif
> }
>
> -#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
> -
> -#else /* !CONFIG_PREEMPT_RT */
> -# include <linux/spinlock_rt.h>
> -#endif /* CONFIG_PREEMPT_RT */
> -
> /*
> * Pull the atomic_t declaration:
> * (asm-mips/atomic.h needs above definitions)
> --
> 2.43.0
>


Nevermind, sent this one by mistake.