[PATCH] spinlock consolidation
This patch (written by me and also containing many suggestions of Arjan van
de Ven) does a major cleanup of the spinlock code. It does the following
things:
- consolidates and enhances the spinlock/rwlock debugging code
- simplifies the asm/spinlock.h files
- encapsulates the raw spinlock type and moves generic spinlock
features (such as ->break_lock) into the generic code.
- cleans up the spinlock code hierarchy to get rid of the spaghetti.
Most notably there's now only a single variant of the debugging code,
located in lib/spinlock_debug.c. (previously we had one SMP debugging
variant per architecture, plus a separate generic one for UP builds)
Also, i've enhanced the rwlock debugging facility, it will now track
write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too.
All locks have lockup detection now, which will work for both soft and hard
spin/rwlock lockups.
The arch-level include files now only contain the minimally necessary
subset of the spinlock code - all the rest that can be generalized now
lives in the generic headers:
include/asm-i386/spinlock_types.h | 16
include/asm-x86_64/spinlock_types.h | 16
I have also split up the various spinlock variants into separate files,
making it easier to see which does what. The new layout is:
SMP | UP
----------------------------|-----------------------------------
asm/spinlock_types_smp.h | linux/spinlock_types_up.h
linux/spinlock_types.h | linux/spinlock_types.h
asm/spinlock_smp.h | linux/spinlock_up.h
linux/spinlock_api_smp.h | linux/spinlock_api_up.h
linux/spinlock.h | linux/spinlock.h
/*
* here's the role of the various spinlock/rwlock related include files:
*
* on SMP builds:
*
* asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
* initializers
*
* linux/spinlock_types.h:
* defines the generic type and initializers
*
* asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
* implementations, mostly inline assembly code
*
* (also included on UP-debug builds:)
*
* linux/spinlock_api_smp.h:
* contains the prototypes for the _spin_*() APIs.
*
* linux/spinlock.h: builds the final spin_*() APIs.
*
* on UP builds:
*
* linux/spinlock_type_up.h:
* contains the generic, simplified UP spinlock type.
* (which is an empty structure on non-debug builds)
*
* linux/spinlock_types.h:
* defines the generic type and initializers
*
* linux/spinlock_up.h:
* contains the __raw_spin_*()/etc. version of UP
* builds. (which are NOPs on non-debug, non-preempt
* builds)
*
* (included on UP-non-debug builds:)
*
* linux/spinlock_api_up.h:
* builds the _spin_*() APIs.
*
* linux/spinlock.h: builds the final spin_*() APIs.
*/
All SMP and UP architectures are converted by this patch.
arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should
be mostly fine.
From: Grant Grundler <grundler@parisc-linux.org>
Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
Builds 32-bit SMP kernel (not booted or tested). I did not try to build
non-SMP kernels. That should be trivial to fix up later if necessary.
I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids
some ugly nesting of linux/*.h and asm/*.h files. Those particular locks
are well tested and contained entirely inside arch specific code. I do NOT
expect any new issues to arise with them.
If someone does ever need to use debug/metrics with them, then they will
need to unravel this hairball between spinlocks, atomic ops, and bit ops
that exist only because parisc has exactly one atomic instruction: LDCW
(load and clear word).
From: "Luck, Tony" <tony.luck@intel.com>
ia64 fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjanv@infradead.org>
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
new file mode 100644
index 0000000..78e6989
--- /dev/null
+++ b/include/linux/spinlock_api_smp.h
@@ -0,0 +1,57 @@
+#ifndef __LINUX_SPINLOCK_API_SMP_H
+#define __LINUX_SPINLOCK_API_SMP_H
+
+#ifndef __LINUX_SPINLOCK_H
+# error "please don't include this file directly"
+#endif
+
+/*
+ * include/linux/spinlock_api_smp.h
+ *
+ * spinlock API declarations on SMP (and debug)
+ * (implemented in kernel/spinlock.c)
+ *
+ * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
+ * Released under the General Public License (GPL).
+ */
+
+int in_lock_functions(unsigned long addr);
+
+#define assert_spin_locked(x) BUG_ON(!spin_is_locked(x))
+
+void __lockfunc _spin_lock(spinlock_t *lock) __acquires(spinlock_t);
+void __lockfunc _read_lock(rwlock_t *lock) __acquires(rwlock_t);
+void __lockfunc _write_lock(rwlock_t *lock) __acquires(rwlock_t);
+void __lockfunc _spin_lock_bh(spinlock_t *lock) __acquires(spinlock_t);
+void __lockfunc _read_lock_bh(rwlock_t *lock) __acquires(rwlock_t);
+void __lockfunc _write_lock_bh(rwlock_t *lock) __acquires(rwlock_t);
+void __lockfunc _spin_lock_irq(spinlock_t *lock) __acquires(spinlock_t);
+void __lockfunc _read_lock_irq(rwlock_t *lock) __acquires(rwlock_t);
+void __lockfunc _write_lock_irq(rwlock_t *lock) __acquires(rwlock_t);
+unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
+ __acquires(spinlock_t);
+unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
+ __acquires(rwlock_t);
+unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
+ __acquires(rwlock_t);
+int __lockfunc _spin_trylock(spinlock_t *lock);
+int __lockfunc _read_trylock(rwlock_t *lock);
+int __lockfunc _write_trylock(rwlock_t *lock);
+int __lockfunc _spin_trylock_bh(spinlock_t *lock);
+void __lockfunc _spin_unlock(spinlock_t *lock) __releases(spinlock_t);
+void __lockfunc _read_unlock(rwlock_t *lock) __releases(rwlock_t);
+void __lockfunc _write_unlock(rwlock_t *lock) __releases(rwlock_t);
+void __lockfunc _spin_unlock_bh(spinlock_t *lock) __releases(spinlock_t);
+void __lockfunc _read_unlock_bh(rwlock_t *lock) __releases(rwlock_t);
+void __lockfunc _write_unlock_bh(rwlock_t *lock) __releases(rwlock_t);
+void __lockfunc _spin_unlock_irq(spinlock_t *lock) __releases(spinlock_t);
+void __lockfunc _read_unlock_irq(rwlock_t *lock) __releases(rwlock_t);
+void __lockfunc _write_unlock_irq(rwlock_t *lock) __releases(rwlock_t);
+void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
+ __releases(spinlock_t);
+void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
+ __releases(rwlock_t);
+void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
+ __releases(rwlock_t);
+
+#endif /* __LINUX_SPINLOCK_API_SMP_H */