Hugh Dickins e504f3fdd6 tmpfs radix_tree: locate_item to speed up swapoff ... We have already acknowledged that swapoff of a tmpfs file is slower than it was before conversion to the generic radix_tree: a little slower there will be acceptable, if the hotter paths are faster. But it was a shock to find swapoff of a 500MB file 20 times slower on my laptop, taking 10 minutes; and at that rate it significantly slows down my testing. Now, most of that turned out to be overhead from PROVE_LOCKING and PROVE_RCU: without those it was only 4 times slower than before; and more realistic tests on other machines don't fare as badly. I've tried a number of things to improve it, including tagging the swap entries, then doing lookup by tag: I'd expected that to halve the time, but in practice it's erratic, and often counter-productive. The only change I've so far found to make a consistent improvement, is to short-circuit the way we go back and forth, gang lookup packing entries into the array supplied, then shmem scanning that array for the target entry. Scanning in place doubles the speed, so it's now only twice as slow as before (or three times slower when the PROVEs are on). So, add radix_tree_locate_item() as an expedient, once-off, single-caller hack to do the lookup directly in place. #ifdef it on CONFIG_SHMEM and CONFIG_SWAP, as much to document its limited applicability as save space in other configurations. And, sadly, #include sched.h for cond_resched(). Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2011-08-03 14:25:24 -10:00
..
lzo	lib: add support for LZO-compressed kernels	2010-01-11 09:34:04 -08:00
raid6	Move .gitignore from drivers/md to lib/raid6	2010-08-30 17:35:52 +10:00
reed_solomon
xz	XZ: Fix missing <linux/kernel.h> include	2011-07-24 10:00:08 -07:00
zlib_deflate	zlib: slim down zlib_deflate() workspace when possible	2011-03-22 17:44:17 -07:00
zlib_inflate	inflate_fast: sout is already a short so ptr arith was off by one.	2010-03-12 15:52:44 -08:00
.gitignore
argv_split.c	tree-wide: convert open calls to remove spaces to skip_spaces() lib function	2009-12-15 08:53:32 -08:00
atomic64_test.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
atomic64.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
audit.c	audit: support the "standard" <asm-generic/unistd.h>	2011-05-04 14:41:28 -04:00
average.c	lib: Improve EWMA efficiency by using bitshifts	2010-12-06 15:58:43 -05:00
bcd.c
bch.c	lib: add shared BCH ECC library	2011-03-11 14:25:50 +00:00
bitmap.c	cpusets: randomize node rotor used in cpuset_mem_spread_node()	2011-07-26 16:49:43 -07:00
bitrev.c
bsearch.c	lib: Add generic binary search function to the kernel.	2011-05-19 16:55:27 +09:30
btree.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
bug.c	modules: Fix module_bug_list list corruption race	2010-10-05 11:29:27 -07:00
bust_spinlocks.c
check_signature.c
checksum.c	lib/checksum.c: optimize do_csum a bit	2011-07-07 04:52:24 -07:00
cmdline.c
cordic.c	lib: cordic: add library module providing cordic angle calculation	2011-06-03 15:01:07 -04:00
cpu_rmap.c	lib: cpu_rmap: CPU affinity reverse-mapping	2011-01-24 14:51:56 -08:00
cpu-notifier-error-inject.c	fault-injection: add CPU notifier error injection module	2010-05-27 09:12:48 -07:00
cpumask.c	cpumask: alloc_cpumask_var() use NUMA_NO_NODE	2011-07-26 16:49:44 -07:00
crc7.c
crc8.c	lib: crc8: add new library module providing crc8 algorithm	2011-06-03 15:01:06 -04:00
crc16.c
crc32.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
crc32defs.h
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c	ctype: constify read-only _ctype string	2009-12-15 08:53:32 -08:00
debug_locks.c	Revert "debug_locks: set oops_in_progress if we will log messages."	2010-11-29 15:18:28 -08:00
debugobjects.c	debugobjects: Fix boot crash when kmemleak and debugobjects enabled	2011-06-20 14:38:43 +02:00
dec_and_lock.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
decompress_bunzip2.c	Decompressors: include <linux/slab.h> in <linux/decompress/mm.h>	2011-01-13 08:03:23 -08:00
decompress_inflate.c	decompressors: check input size in decompress_inflate.c	2011-01-13 08:03:25 -08:00
decompress_unlzma.c	Decompressors: validate match distance in decompress_unlzma.c	2011-01-13 08:03:24 -08:00
decompress_unlzo.c	Decompressors: fix callback-to-callback mode in decompress_unlzo.c	2011-01-13 08:03:24 -08:00
decompress_unxz.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
decompress.c	decompressors: add boot-time XZ support	2011-01-13 08:03:25 -08:00
devres.c	devres: fix possible use after free	2011-07-25 20:57:14 -07:00
div64.c	div64_u64(): improve precision on 32bit platforms	2010-10-26 16:52:19 -07:00
dma-debug.c	dma-debug: print information about leaked entry	2011-04-07 16:31:19 +02:00
dump_stack.c
dynamic_debug.c	dynamic_debug: add #include <linux/sched.h>	2011-02-03 15:59:58 -08:00
extable.c	module: trim exception table on init free.	2009-06-12 21:47:04 +09:30
fault-inject.c	fault-injection: add ability to export fault_attr in arbitrary directory	2011-08-03 14:25:20 -10:00
find_last_bit.c	bitops: add #ifndef for each of find bitops	2011-05-26 17:12:38 -07:00
find_next_bit.c	arch: remove CONFIG_GENERIC_FIND_{NEXT_BIT,BIT_LE,LAST_BIT}	2011-05-26 17:12:38 -07:00
flex_array.c	flex_array: avoid divisions when accessing elements	2011-05-26 17:12:33 -07:00
gcd.c	lib: add lib/gcd.c	2009-06-18 13:04:05 -07:00
gen_crc32table.c	crc32: major optimization	2010-05-25 08:07:06 -07:00
genalloc.c	lib/genalloc.c: add support for specifying the physical address	2011-05-25 08:39:54 -07:00
halfmd4.c
hexdump.c	include/linux/printk.h lib/hexdump.c: neatening and add CONFIG_PRINTK guard	2011-01-13 08:03:10 -08:00
hweight.c	x86: Add optimized popcnt variants	2010-04-06 15:52:11 -07:00
idr.c	ida: simplified functions for id allocation	2011-08-03 14:25:20 -10:00
inflate.c	MN10300: Don't try and #include <linux/slab.h> in lib/inflate.c from bootloader	2010-08-12 09:51:35 -07:00
int_sqrt.c
iomap_copy.c
iomap.c	iomap: make IOPORT/PCI mapping functions conditional	2011-07-22 18:46:26 +02:00
iommu-helper.c	iommu: inline iommu_num_pages	2010-08-09 20:45:05 -07:00
ioremap.c	ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support	2011-01-12 03:06:19 -05:00
irq_regs.c
is_single_threaded.c	kernel: is_current_single_threaded: don't use ->mmap_sem	2009-07-17 09:11:31 +10:00
kasprintf.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
Kconfig	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem	2011-06-08 13:44:21 -04:00
Kconfig.debug	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-07-22 16:45:02 -07:00
Kconfig.kgdb	mips,kgdb: kdb low level trap catch and stack trace	2010-05-20 21:04:26 -05:00
Kconfig.kmemcheck	kmemcheck: depend on HAVE_ARCH_KMEMCHECK	2009-07-01 22:28:44 +02:00
klist.c
kobject_uevent.c	kobject_uevent: fix typo in comments	2010-08-23 18:12:46 -07:00
kobject.c	Delay struct net freeing while there's a sysfs instance refering to it	2011-06-12 17:45:41 -04:00
kref.c	kref: Add a kref_sub function	2010-11-22 13:25:13 +10:00
kstrtox.c	lib: make _tolower() public	2011-07-25 20:57:16 -07:00
lcm.c	lib/lcm.c: quiet sparse noise	2011-07-25 20:57:15 -07:00
libcrc32c.c
list_debug.c	Expand CONFIG_DEBUG_LIST to several other list operations	2011-02-18 11:32:28 -08:00
list_sort.c	lib/list_sort: test: check element addresses	2010-10-26 16:52:19 -07:00
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	rcu: Fix unpaired rcu_irq_enter() from locking selftests	2011-05-26 09:42:19 -07:00
lru_cache.c	lru_cache: use correct type in sizeof for allocation	2011-05-25 08:39:52 -07:00
Makefile	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem	2011-06-08 13:44:21 -04:00
nlattr.c	net: fix nla_policy_len to actually _iterate_ over the policy	2011-02-28 12:38:25 -08:00
parser.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
percpu_counter.c	percpucounter: Optimize __percpu_counter_add a bit through the use of this_cpu() options.	2010-12-17 15:07:18 +01:00
plist.c	plist: Remove the need to supply locks to plist heads	2011-07-08 14:02:53 +02:00
prio_heap.c
prio_tree.c
proportions.c
radix-tree.c	tmpfs radix_tree: locate_item to speed up swapoff	2011-08-03 14:25:24 -10:00
random32.c	Merge branch 'master' into for-next	2010-06-16 18:08:13 +02:00
ratelimit.c	ratelimit: fix the return value when __ratelimit() fails to acquire the lock	2010-04-07 08:38:04 -07:00
rational.c	lib/rational.c needs module.h	2010-01-11 09:34:05 -08:00
rbtree.c	Export the augmented rbtree helper functions	2011-01-28 12:16:59 +10:00
reciprocal_div.c
rwsem-spinlock.c	rwsem generic spinlock: use IRQ save/restore spinlocks	2010-04-07 16:15:05 -07:00
rwsem.c	rwsem: Remove redundant asmregparm annotation	2011-01-27 12:30:40 +01:00
scatterlist.c	scatterlist: prevent invalid free when alloc fails	2010-08-30 19:55:09 +02:00
sha1.c
show_mem.c	arch, mm: filter disallowed nodes from arch specific show_mem functions	2011-05-25 08:39:03 -07:00
smp_processor_id.c
sort.c
spinlock_debug.c	locking: Further name space cleanups	2009-12-14 23:55:33 +01:00
string_helpers.c
string.c	Add a strtobool function matching semantics of existing in kernel equivalents	2011-05-19 16:55:28 +09:30
swiotlb.c	swiotlb: Export swioltb_nr_tbl and utilize it as appropiate.	2011-06-06 15:41:16 -04:00
syscall.c
test-kstrtox.c	kstrtox: fix compile warnings in test	2011-04-14 16:06:54 -07:00
textsearch.c	textsearch: doc - fix spelling in lib/textsearch.c.	2011-01-24 23:33:30 -08:00
timerqueue.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
ts_bm.c
ts_fsm.c
ts_kmp.c
uuid.c	Unified UUID/GUID definition	2010-05-19 22:40:47 -04:00
vsprintf.c	Merge 'akpm' patch series	2011-07-25 21:00:19 -07:00