Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Rasmus Villemoes 7c43d9a30c lib/vsprintf.c: even faster binary to decimal conversion ... The most expensive part of decimal conversion is the divisions by 10 (albeit done using reciprocal multiplication with appropriately chosen constants). I decided to see if one could eliminate around half of these multiplications by emitting two digits at a time, at the cost of a 200 byte lookup table, and it does indeed seem like there is something to be gained, especially on 64 bits. Microbenchmarking shows improvements ranging from -50% (for numbers uniformly distributed in [0, 2^64-1]) to -25% (for numbers heavily biased toward the smaller end, a more realistic distribution). On a larger scale, perf shows that top, one of the big consumers of /proc data, uses 0.5-1.0% fewer cpu cycles. I had to jump through some hoops to get the 32 bit code to compile and run on my 64 bit machine, so I'm not sure how relevant these numbers are, but just for comparison the microbenchmark showed improvements between -30% and -10%. The bloat-o-meter costs are around 150 bytes (the generated code is a little smaller, so it's not the full 200 bytes) on both 32 and 64 bit. I'm aware that extra cache misses won't show up in a microbenchmark as used above, but on the other hand decimal conversions often happen in bulk (for example in the case of top). I have of course tested that the new code generates the same output as the old, for both the first and last 1e10 numbers in [0,2^64-1] and 4e9 'random' numbers in-between. Test and verification code on github: https://github.com/Villemoes/dec. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Tested-by: Jeff Epler <jepler@unpythonic.net> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-04-17 09:03:54 -04:00
..
fonts	fonts: Add 6x10 font	2014-10-09 11:35:48 +03:00
lz4	lib/lz4: Pull out constant tables	2015-03-25 15:04:57 +01:00
lzo	lzo: check for length overrun in variable length encoding.	2014-09-28 11:08:01 +02:00
mpi	MPILIB: Fix comparison of negative MPIs	2015-01-14 16:10:12 +00:00
raid6	x86/raid6: correctly check for assembler capabilities	2015-02-04 08:35:51 +11:00
reed_solomon
xz	lib/xz: enable all filters by default in Kconfig	2014-06-04 16:54:18 -07:00
zlib_deflate	zlib: clean up some dead code	2014-08-06 18:01:24 -07:00
zlib_inflate	zlib: clean up some dead code	2014-08-06 18:01:24 -07:00
.gitignore
argv_split.c	argv_split(): teach it to handle mutable strings	2013-04-29 18:28:19 -07:00
asn1_decoder.c	lib/asn1_decoder.c: kernel-doc warning fix	2014-06-04 16:54:19 -07:00
assoc_array.c	assoc_array: Include rcupdate.h for call_rcu() definition	2015-01-07 16:08:41 +00:00
atomic64.c	locking,arch: Rewrite generic atomic support	2014-08-14 12:48:14 +02:00
atomic64_test.c	lib/atomic64_test.c: convert printk(KERN_INFO to pr_info	2014-06-04 16:54:19 -07:00
audit.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
average.c	lib: Ensure EWMA does not store wrong intermediate values	2014-01-16 23:46:06 -08:00
bcd.c
bch.c
bitmap.c	bitmap, cpumask, nodemask: remove dedicated formatting functions	2015-02-13 21:21:39 -08:00
bitrev.c	ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction	2014-12-22 16:43:06 +00:00
bsearch.c
btree.c	lib/btree.c: fix leak of whole btree nodes	2014-06-04 16:54:18 -07:00
bug.c	lib/bug: Use RCU list ops for module_bug_list	2014-11-11 17:07:46 +10:30
build_OID_registry	X.509: do not emit any informational output	2013-06-19 17:54:06 +02:00
bust_spinlocks.c
check_signature.c
checksum.c	lib/checksum.c: fix build for generic csum_tcpudp_nofold	2015-01-29 11:57:38 -08:00
clz_ctz.c	lib/clz_ctz.c: add prototype declarations in lib/clz_ctz.c	2014-04-03 16:21:12 -07:00
clz_tab.c
cmdline.c	lib: Add a generic cmdline parse function parse_option_str	2014-10-03 18:40:58 +01:00
compat_audit.c	audit: Add generic compat syscall support	2014-03-20 10:11:35 -04:00
cordic.c
cpu-notifier-error-inject.c
cpu_rmap.c	Remove GENERIC_HARDIRQ config option	2013-09-13 15:09:52 +02:00
cpumask.c	lib/cpumask: cpumask_set_cpu_local_first to use all cores when numa node is not defined	2014-07-02 18:29:23 -07:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c	crypto: crct10dif - Add fallback for broken initrds	2013-09-12 15:31:34 +10:00
crc7.c	lib/crc7: Shift crc7() output left 1 bit	2014-05-16 14:26:52 -04:00
crc8.c
crc16.c
crc32.c	lib: crc32: Add some additional __pure annotations	2014-06-25 16:04:00 -07:00
crc32defs.h
ctype.c
debug_locks.c	mutex: Add support for wound/wait style locks	2013-06-26 12:10:56 +02:00
debugobjects.c	lib/debugobjects.c: convert printk(KERN_DEBUG to pr_debug	2014-06-04 16:53:53 -07:00
dec_and_lock.c
decompress.c	lib/decompress.c: consistency of compress formats for kernel image	2014-12-13 12:42:52 -08:00
decompress_bunzip2.c	decompress_bunzip2: off by one in get_next_block()	2014-12-13 12:42:52 -08:00
decompress_inflate.c	initramfs: support initramfs that is bigger than 2GiB	2014-08-08 15:57:26 -07:00
decompress_unlz4.c	initramfs: support initramfs that is bigger than 2GiB	2014-08-08 15:57:26 -07:00
decompress_unlzma.c	initramfs: support initramfs that is bigger than 2GiB	2014-08-08 15:57:26 -07:00
decompress_unlzo.c	initramfs: support initramfs that is bigger than 2GiB	2014-08-08 15:57:26 -07:00
decompress_unxz.c	initramfs: support initramfs that is bigger than 2GiB	2014-08-08 15:57:26 -07:00
devres.c	devres: support sizes greater than an unsigned long	2014-11-07 10:09:07 -08:00
digsig.c	lib/digsig.c: kernel-doc warning fixes	2014-06-04 16:54:19 -07:00
div64.c	lib: correct link to the original source for div64_u64	2015-03-06 23:19:27 +01:00
dma-debug.c	dma-debug: prevent early callers from crashing	2014-12-10 17:41:02 -08:00
dump_stack.c	asmlinkage: Add explicit __visible to drivers/*, lib/*, kernel/*	2014-05-05 16:07:46 -07:00
dynamic_debug.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2015-02-10 18:57:15 -08:00
dynamic_queue_limits.c	lib/dynamic_queue_limits.c: simplify includes	2015-02-12 18:54:15 -08:00
earlycpio.c	earlycpio.c: Fix the confusing comment of find_cpio_data().	2013-08-14 23:24:01 +02:00
extable.c
fault-inject.c	fault-inject: add ratelimit option	2014-12-13 12:42:52 -08:00
fdt.c
fdt_empty_tree.c	lib: add fdt_empty_tree.c	2014-04-30 19:49:37 +01:00
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
find_bit.c	lib: rename lib/find_next_bit.c to lib/find_bit.c	2015-04-17 09:03:54 -04:00
find_last_bit.c	lib: find_*_bit reimplementation	2015-04-17 09:03:53 -04:00
flex_array.c	reciprocal_divide: update/correction of the algorithm	2014-01-21 23:17:20 -08:00
flex_proportions.c	proportions: add @gfp to init functions	2014-09-08 09:51:30 +09:00
gcd.c
gen_crc32table.c	lib: crc32: constify crc32 lookup table	2015-02-13 21:21:35 -08:00
genalloc.c	lib/genalloc.c: check result of devres_alloc()	2015-02-13 21:21:36 -08:00
glob.c	lib/glob.c: add CONFIG_GLOB_SELFTEST	2014-08-06 18:01:25 -07:00
halfmd4.c	lib/halfmd4.c: simplify includes	2015-02-12 18:54:15 -08:00
hexdump.c	hexdump: make it return number of bytes placed in buffer	2015-02-12 18:54:15 -08:00
hweight.c	Make ARCH_HAS_FAST_MULTIPLIER a real config variable	2014-09-13 11:14:53 -07:00
idr.c	lib/idr.c: remove redundant include	2015-02-12 18:54:15 -08:00
inflate.c
int_sqrt.c	lib/int_sqrt.c: optimize square root algorithm	2013-04-29 18:28:19 -07:00
interval_tree.c	lib/interval_tree.c: simplify includes	2015-02-12 18:54:15 -08:00
interval_tree_test.c	lib: Export interval_tree	2014-05-05 09:09:14 +02:00
iomap.c	Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP	2014-04-07 16:36:11 -07:00
iomap_copy.c
iommu-helper.c
ioremap.c	x86, mm: support huge KVA mappings on x86	2015-04-14 16:49:04 -07:00
iov_iter.c	Merge branch 'iov_iter' into for-next	2015-04-11 22:26:51 -04:00
irq_regs.c
is_single_threaded.c
jedec_ddr_data.c
kasprintf.c
Kconfig	Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild	2015-02-19 10:36:45 -08:00
Kconfig.debug	Merge branch 'akpm' (patches from Andrew)	2015-04-14 16:49:17 -07:00
Kconfig.kasan	kasan: enable instrumentation of global variables	2015-02-13 21:21:42 -08:00
Kconfig.kgdb	kdb: Allow access to sensitive commands to be restricted by default	2014-11-11 09:31:52 -06:00
Kconfig.kmemcheck
kfifo.c	kfifo: use BUG_ON	2014-08-08 15:57:25 -07:00
klist.c	klist: use same naming scheme as hlist for klist_add_after()	2014-08-06 18:01:24 -07:00
kobject.c	kobject: WARN as tip when call kobject_get() to a kobject not initialized	2015-03-25 15:26:49 +01:00
kobject_uevent.c	lib/kobject_uevent.c: remove redundant include	2015-02-12 18:54:15 -08:00
kstrtox.c	lib/kstrtox.c: remove redundant cleanup	2014-01-23 16:36:57 -08:00
kstrtox.h
lcm.c	block: fix blk_stack_limits() regression due to lcm() change	2015-03-31 09:45:50 -06:00
libcrc32c.c	crypto: LLVMLinux: Remove VLAIS usage from libcrc32c.c	2014-10-14 10:51:23 +02:00
list_debug.c
list_sort.c	lib/list_sort.c: rearrange includes	2015-02-12 18:54:15 -08:00
llist.c	lib/llist.c: remove redundant include	2015-02-12 18:54:15 -08:00
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	locking/lockdep: Revert qrwlock recusive stuff	2014-10-03 06:09:30 +02:00
lockref.c	locking: Remove ACCESS_ONCE() usage	2015-02-24 08:44:16 +01:00
lru_cache.c	lru_cache: remove use of seq_printf return value	2015-04-15 16:35:25 -07:00
Makefile	lib: rename lib/find_next_bit.c to lib/find_bit.c	2015-04-17 09:03:54 -04:00
md5.c	lib/md5.c: simplify include	2015-02-12 18:54:15 -08:00
memory-notifier-error-inject.c
memweight.c
net_utils.c	mac_pton: Use bool not int return	2014-06-25 17:45:43 -07:00
nlattr.c	netlink: pad nla_memcpy dest buffer with zeroes	2015-03-31 14:07:24 -04:00
notifier-error-inject.c	mode_t, whack-a-mole at 11...	2013-04-09 14:13:05 -04:00
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c	Give the OID registry file module info to avoid kernel tainting	2013-05-05 14:38:00 -07:00
parser.c	lib/parser.c: put EXPORT_SYMBOLs in the conventional place	2014-01-23 16:36:55 -08:00
pci_iomap.c	pci: add pci_iomap_range	2015-01-21 16:28:49 +10:30
percpu-refcount.c	percpu_ref: make INIT_ATOMIC and switch_to_atomic() sticky	2014-09-24 13:31:50 -04:00
percpu_counter.c	percpu_counter: add @gfp to percpu_counter_init()	2014-09-08 09:51:29 +09:00
percpu_ida.c	lib/percpu_ida.c: remove redundant includes	2015-02-12 18:54:16 -08:00
percpu_test.c	percpu: add test module for various percpu operations	2013-11-13 12:09:11 +09:00
plist.c	lib/plist.c: remove redundant include	2015-02-12 18:54:16 -08:00
pm-notifier-error-inject.c
proportions.c	proportions: add @gfp to init functions	2014-09-08 09:51:30 +09:00
radix-tree.c	lib/radix-tree.c: change to simpler include	2015-02-12 18:54:16 -08:00
random32.c	random32: improvements to prandom_bytes	2014-08-24 18:36:01 -07:00
ratelimit.c
rational.c
rbtree.c	lib/rbtree.c: fix typo in comment of __rb_insert()	2014-08-08 15:57:24 -07:00
rbtree_test.c	rbtree/test: test rbtree_postorder_for_each_entry_safe()	2014-01-23 16:37:03 -08:00
reciprocal_div.c	reciprocal_divide: update/correction of the algorithm	2014-01-21 23:17:20 -08:00
rhashtable.c	rhashtable: provide len to obj_hashfn	2015-03-25 17:18:33 +01:00
scatterlist.c	lib/scatterlist: fix memory leak with scsi-mq	2014-10-28 10:27:10 -06:00
seq_buf.c	seq_buf: Fix seq_buf_bprintf() truncation	2015-03-04 23:40:19 -05:00
sha1.c	lib: EXPORT_SYMBOL sha_init	2015-03-23 22:12:08 -04:00
show_mem.c	lib/show_mem.c: remove redundant include	2015-02-12 18:54:16 -08:00
smp_processor_id.c	percpu: add preemption checks to __this_cpu ops	2014-04-07 16:36:14 -07:00
sort.c	lib/sort.c: move include inside #if 0	2015-02-12 18:54:16 -08:00
stmp_device.c	lib/stmp_device.c: replace module.h include	2015-02-12 18:54:16 -08:00
string.c	lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR	2015-03-20 07:56:12 +11:00
string_helpers.c	lib/string_helpers.c: change semantics of string_escape_mem	2015-04-15 16:35:24 -07:00
strncpy_from_user.c	lib/strncpy_from_user.c: replace module.h include	2015-02-12 18:54:16 -08:00
strnlen_user.c
swiotlb.c	swiotlb: don't assume PA 0 is invalid	2014-06-20 16:04:32 -04:00
syscall.c	lib/syscall.c: unexport task_current_syscall()	2014-04-03 16:21:06 -07:00
test-hexdump.c	lib/test-hexdump.c: fix initconst confusion	2015-04-15 16:35:22 -07:00
test-kstrtox.c	lib/test-kstrtox.c: use ARRAY_SIZE instead of sizeof/sizeof[0]	2014-08-06 18:01:25 -07:00
test-string_helpers.c	lib/string_helpers.c: change semantics of string_escape_mem	2015-04-15 16:35:24 -07:00
test_bpf.c	test: bpf: expand DIV_KX to DIV_MOD_KX	2014-12-08 20:23:22 -05:00
test_firmware.c	test: add firmware_class loader test	2014-07-17 18:44:19 -07:00
test_kasan.c	lib: add kasan test module	2015-02-13 21:21:41 -08:00
test_module.c	test: add minimal module for verification testing	2014-01-23 16:36:57 -08:00
test_rhashtable.c	test_rhashtable: Remove bogus max_size setting	2015-04-03 15:09:36 -04:00
test_user_copy.c	test: check copy_to/from_user boundary validation	2014-01-23 16:36:57 -08:00
textsearch.c	lib/textsearch.c: remove textsearch_put reference from comments	2014-10-14 02:18:14 +02:00
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ucs2_string.c	Move utf16 functions to kernel core and rename	2013-04-15 21:23:03 +01:00
usercopy.c	Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS	2013-04-30 17:04:09 -07:00
uuid.c	uuid: use prandom_bytes()	2013-04-29 18:28:42 -07:00
vsprintf.c	lib/vsprintf.c: even faster binary to decimal conversion	2015-04-17 09:03:54 -04:00