the latest version of the spinlock consolidation patch can be found at:
http://redhat.com/~mingo/spinlock-patches/consolidate-spinlocks.patch
the patch is now complete in the sense that it does everything i wanted
it to do. If you have any other suggestions (or i have missed to
incorporate an earlier suggestion of yours), please yell.
Changes:
- all architectures have been converted to the new spinlock code.
arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers. Alpha, m32r, mips, parisc, sh, sparc, sparc64 has
not been tested yet, but should be mostly fine. x86 and x64 was
boot-tested in all relevant .config variations. It all brought a nice
reduction in source code size:
62 files changed, 1455 insertions(+), 3025 deletions(-)
Al, would you be interested in checking this patch on your build
farm? It should build on all architectures, UP and SMP alike.
(NOTE: i've switched sparc32, sparc64, alpha, ppc, parisc to use the
generic spinlock debugging code. I believe the generic debugging
code is now capable enough to be a replacement - but especially the
Sparc ones are pretty advanced; so if i've missed some important
feature please let me know and i'll implement it in the generic
code.)
- linux/spinlock_types.h: new, pure header file that can be used
by other headers to define spinlock fields - without having to
pull in all the other include files that are needed on the
implementational side. (Roman Zippel)
- lib/spinlock_debug.c: got rid of the __FILE__/__LINE__ debug output
(suggested by Ingo Oeser), and streamlined the debug output.
Implemented 'lockup detection' which is a must for architectures that
dont have the equivalent of an NMI watchdog. (but is useful on other
architectures as well.) Both spinlocks and rwlocks are now fully
debugged.
- linux/spinlock.h: got rid of the ATOMIC_DEC_AND_LOCK cruft. This is
achieved by not doing the UP-nonpreempt-nondebug specific
optimization but letting it pick the generic _atomic_dec_and_lock
function. The assembly looks sane on x86 (no locked ops, etc.) so
there's no performance problem. Other architectures should work fine
too, those which implement _atomic_dec_and_lock unconditionally might
want to review whether they want to use the CONFIG_HAVE_DEC_LOCK
mechanism to get the optimized (generic) version of the function on
UP.
- asm-generic/spinlock_types_up.h: further simplifications (suggested
by Arjan van de Ven), typo fixed
- linux/spinlock_up.h: since this an UP-nondebug branch now, the macros
were simplified and streamlined significantly.
- asm-generic/spinlock_up.h: further cleanups, reordering of op
definitions into 'natural' op order.
- asm-i386/spinlock.h and asm-x86_64/spinlock.h: reordering of ops,
cleanups
- include/linux/spinlock.h: more cleanups, reordering
- linux/spinlock_smp.h: cleanups, reordering of prototypes
- kernel/spinlock.c: fixed bug in generic_raw_read_trylock and renamed
it to generic__raw_read_trylock to ease conversion.
- lib/kernel_lock.c: simplification
- (lots of small details i forgot)
Ingo
