Linus Torvalds 8e3e076c5a BKL: revert back to the old spinlock implementation ... The generic semaphore rewrite had a huge performance regression on AIM7 (and potentially other BKL-heavy benchmarks) because the generic semaphores had been rewritten to be simple to understand and fair. The latter, in particular, turns a semaphore-based BKL implementation into a mess of scheduling. The attempt to fix the performance regression failed miserably (see the previous commit 00b41ec261 'Revert "semaphore: fix"'), and so for now the simple and sane approach is to instead just go back to the old spinlock-based BKL implementation that never had any issues like this. This patch also has the advantage of being reported to fix the regression completely according to Yanmin Zhang, unlike the semaphore hack which still left a couple percentage point regression. As a spinlock, the BKL obviously has the potential to be a latency issue, but it's not really any different from any other spinlock in that respect. We do want to get rid of the BKL asap, but that has been the plan for several years. These days, the biggest users are in the tty layer (open/release in particular) and Alan holds out some hope: "tty release is probably a few months away from getting cured - I'm afraid it will almost certainly be the very last user of the BKL in tty to get fixed as it depends on everything else being sanely locked." so while we're not there yet, we do have a plan of action. Tested-by: Yanmin Zhang <yanmin_zhang@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Alexander Viro <viro@ftp.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2008-05-10 20:58:02 -07:00
..
lzo
reed_solomon
zlib_deflate
zlib_inflate
.gitignore
argv_split.c
audit.c
bitmap.c	mempolicy: add bitmap_onto() and bitmap_fold() operations	2008-04-28 08:58:19 -07:00
bitrev.c
bug.c
bust_spinlocks.c
check_signature.c
cmdline.c
cpumask.c
crc-ccitt.c
crc-itu-t.c
crc7.c
crc16.c
crc32.c
crc32defs.h
ctype.c
debug_locks.c
debugobjects.c	infrastructure to debug (dynamic) objects	2008-04-30 08:29:53 -07:00
dec_and_lock.c
devres.c	[POWERPC] devres: Add devm_ioremap_prot()	2008-05-05 16:47:14 +10:00
div64.c	rename div64_64 to div64_u64	2008-05-01 08:03:58 -07:00
dump_stack.c
extable.c
fault-inject.c
find_next_bit.c	bitops: remove "optimizations"	2008-04-29 08:11:16 -07:00
gen_crc32table.c
genalloc.c
halfmd4.c
hexdump.c
hweight.c
idr.c	idr: fix idr_remove()	2008-05-01 08:04:00 -07:00
inflate.c	lib/inflate.c: handle failed malloc()	2008-04-29 08:06:02 -07:00
int_sqrt.c
iomap_copy.c
iomap.c	iomap: fix 64 bits resources on 32 bits	2008-04-29 08:06:02 -07:00
iommu-helper.c
ioremap.c
irq_regs.c
kasprintf.c
Kconfig	x86, bitops: select the generic bitmap search functions	2008-04-26 19:21:17 +02:00
Kconfig.debug	debugobjects: add timer specific object debugging code	2008-04-30 08:29:53 -07:00
Kconfig.kgdb	kgdb: kconfig fix xconfig/menuconfig element	2008-05-05 07:13:21 -05:00
kernel_lock.c	BKL: revert back to the old spinlock implementation	2008-05-10 20:58:02 -07:00
klist.c	klist: fix coding style errors in klist.h and klist.c	2008-04-30 16:52:58 -07:00
kobject_uevent.c	lib: replace remaining __FUNCTION__ occurrences	2008-04-30 08:29:54 -07:00
kobject.c	kobject: do not copy vargs, just pass them around	2008-04-30 16:52:48 -07:00
kref.c
libcrc32c.c
list_debug.c
lmb.c	[POWERPC] Provide walk_memory_resource() for powerpc	2008-04-29 15:57:53 +10:00
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
Makefile	infrastructure to debug (dynamic) objects	2008-04-30 08:29:53 -07:00
parser.c
percpu_counter.c	mm: bdi: export BDI attributes in sysfs	2008-04-30 08:29:49 -07:00
plist.c
prio_heap.c
prio_tree.c
proportions.c	mm: bdi: allow setting a maximum for the bdi dirty limit	2008-04-30 08:29:50 -07:00
radix-tree.c	Remove set_migrateflags()	2008-04-28 08:58:17 -07:00
random32.c
ratelimit.c	isolate ratelimit from printk.c for other use	2008-04-29 08:06:06 -07:00
rbtree.c
reciprocal_div.c
rwsem-spinlock.c
rwsem.c
scatterlist.c
sha1.c
smp_processor_id.c
sort.c
spinlock_debug.c
string.c	Add a new sysfs_streq() string comparison function	2008-05-01 08:03:59 -07:00
swiotlb.c	dma/ia64: update ia64 machvecs, swiotlb.c	2008-04-29 08:06:12 -07:00
textsearch.c
ts_bm.c
ts_fsm.c
ts_kmp.c
vsprintf.c