linux.git/include/linux/rbtree_types.h, branch v7.0 Linux kernel source tree rbtree: Split out the rbtree type definitions into <linux/rbtree_types.h> 2021-08-17T15:36:48+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2021-08-15T21:28:19+00:00 089050cafa10f408c9e18ad53965db839b894840 So we have this header dependency problem on RT: - <linux/rtmutex.h> needs the definition of 'struct rb_root_cached'. - <linux/rbtree.h> includes <linux/kernel.h>, which includes <linux/spinlock.h>. That works nicely for non-RT enabled kernels, but on RT enabled kernels spinlocks are based on rtmutexes, which creates another circular header dependency, as <linux/spinlocks.h> will require <linux/rtmutex.h>. Split out the type definitions and move them into their own header file so the rtmutex header can include just those. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211303.542123501@linutronix.de 
So we have this header dependency problem on RT:

 - <linux/rtmutex.h> needs the definition of 'struct rb_root_cached'.
 - <linux/rbtree.h> includes <linux/kernel.h>, which includes <linux/spinlock.h>.

That works nicely for non-RT enabled kernels, but on RT enabled kernels
spinlocks are based on rtmutexes, which creates another circular header
dependency, as <linux/spinlocks.h> will require <linux/rtmutex.h>.

Split out the type definitions and move them into their own header file so
the rtmutex header can include just those.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.542123501@linutronix.de