linux/lib
Herbert Xu 07ee0722bf rhashtable: Add cap on number of elements in hash table
We currently have no limit on the number of elements in a hash table.
This is a problem because some users (tipc) set a ceiling on the
maximum table size and when that is reached the hash table may
degenerate.  Others may encounter OOM when growing and if we allow
insertions when that happens the hash table perofrmance may also
suffer.

This patch adds a new paramater insecure_max_entries which becomes
the cap on the table.  If unset it defaults to max_size * 2.  If
it is also zero it means that there is no cap on the number of
elements in the table.  However, the table will grow whenever the
utilisation hits 100% and if that growth fails, you will get ENOMEM
on insertion.

As allowing oversubscription is potentially dangerous, the name
contains the word insecure.

Note that the cap is not a hard limit.  This is done for performance
reasons as enforcing a hard limit will result in use of atomic ops
that are heavier than the ones we currently use.

The reasoning is that we're only guarding against a gross over-
subscription of the table, rather than a small breach of the limit.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-16 18:08:26 -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 md/raid6 algorithms: xor_syndrome() for SSE2 2015-04-22 08:00:42 +10:00
reed_solomon
xz
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
asn1_decoder.c
assoc_array.c assoc_array: Include rcupdate.h for call_rcu() definition 2015-01-07 16:08:41 +00:00
atomic64_test.c
atomic64.c locking,arch: Rewrite generic atomic support 2014-08-14 12:48:14 +02:00
audit.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
average.c
bcd.c
bch.c
bitmap.c lib/bitmap.c: bitmap_[empty,full]: remove code duplication 2015-04-17 09:03:56 -04:00
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
bug.c lib/bug: Use RCU list ops for module_bug_list 2014-11-11 17:07:46 +10:30
build_OID_registry
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
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
cordic.c
cpu_rmap.c
cpu-notifier-error-inject.c
cpumask.c This is the final removal (after several years!) of the obsolete cpus_* 2015-04-20 10:19:03 -07:00
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c
debug_locks.c
debugobjects.c
dec_and_lock.c
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
decompress.c lib/decompress.c: consistency of compress formats for kernel image 2014-12-13 12:42:52 -08:00
devres.c lib: devres: add a helper function for ioremap_wc 2015-03-16 21:11:32 +01:00
digsig.c
div64.c lib: correct link to the original source for div64_u64 2015-03-06 23:19:27 +01:00
dma-debug.c lib/dma-debug: fix bucket_find_contain() 2015-04-17 09:03:54 -04:00
dump_stack.c
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
extable.c
fault-inject.c fault-inject: add ratelimit option 2014-12-13 12:42:52 -08:00
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit.c lib: rename lib/find_next_bit.c to lib/find_bit.c 2015-04-17 09:03:54 -04:00
flex_array.c
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
interval_tree_test.c
interval_tree.c lib/interval_tree.c: simplify includes 2015-02-12 18:54:15 -08:00
iomap_copy.c
iomap.c
iommu-common.c iommu-common: rename iommu_pool_hash to iommu_hash_common 2015-04-20 14:09:55 -04:00
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 This is the final removal (after several years!) of the obsolete cpus_* 2015-04-20 10:19:03 -07:00
Kconfig.debug Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-05-06 10:26:37 -07:00
Kconfig.kasan kasan: show gcc version requirements in Kconfig and Documentation 2015-05-05 17:10:10 -07:00
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_uevent.c lib/kobject_uevent.c: remove redundant include 2015-02-12 18:54:15 -08:00
kobject.c kobject: WARN as tip when call kobject_get() to a kobject not initialized 2015-03-25 15:26:49 +01:00
kstrtox.c
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 Break up monolithic iommu table/lock into finer graularity pools and lock 2015-04-18 12:32:59 -07:00
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
nlattr.c netlink: pad nla_memcpy dest buffer with zeroes 2015-03-31 14:07:24 -04:00
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c
parser.c
pci_iomap.c pci: add pci_iomap_range 2015-01-21 16:28:49 +10:30
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-refcount.c percpu_ref: make INIT_ATOMIC and switch_to_atomic() sticky 2014-09-24 13:31:50 -04:00
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_test.c
rbtree.c lib/rbtree.c: fix typo in comment of __rb_insert() 2014-08-08 15:57:24 -07:00
reciprocal_div.c
rhashtable.c rhashtable: Add cap on number of elements in hash table 2015-05-16 18:08:26 -04:00
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
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_helpers.c SCSI misc on 20150416 2015-04-16 19:02:04 -04:00
string.c lib: make memzero_explicit more robust against dead store elimination 2015-05-04 17:49:51 +08:00
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
syscall.c
test_bpf.c test: bpf: expand DIV_KX to DIV_MOD_KX 2014-12-08 20:23:22 -05:00
test_firmware.c
test_kasan.c lib: add kasan test module 2015-02-13 21:21:41 -08:00
test_module.c
test_rhashtable.c test_rhashtable: Remove bogus max_size setting 2015-04-03 15:09:36 -04:00
test_user_copy.c
test-hexdump.c hexdump: avoid warning in test function 2015-04-19 13:48:40 -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
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
usercopy.c
uuid.c
vsprintf.c lib/vsprintf.c: improve put_dec_trunc8 slightly 2015-04-17 09:03:55 -04:00