This patch deinlines jhash and jhash2. It also removes rhashtable_jhash2(key, length, seed) because it was merely calling jhash2(key, length, seed).
With this .config: http://busybox.net/~vda/kernel_config, after deinlining these functions have sizes and callsite counts as follows: jhash: 297 bytes, 111 calls jhash2: 205 bytes, 136 calls Total size decrease is about 33,000 bytes: text data bss dec hex filename 90663567 17221960 36659200 144544727 89d93d7 vmlinux5 90630370 17221864 36659200 144511434 89d11ca vmlinux.after Signed-off-by: Denys Vlasenko <dvlas...@redhat.com> CC: Thomas Graf <tg...@suug.ch> CC: David Miller <da...@davemloft.net> CC: Tom Herbert <t...@herbertland.com> CC: Alexander Duyck <alexander.h.du...@redhat.com> CC: Jozsef Kadlecsik <kad...@blackhole.kfki.hu> CC: Herbert Xu <herb...@gondor.apana.org.au> CC: netdev@vger.kernel.org CC: linux-ker...@vger.kernel.org --- Changes in v2: created a new source file, jhash.c Changes in v3: do not deinline __jhash_nwords; use EXPORT_SYMBOL instead of EXPORT_SYMBOL_GPL include/linux/jhash.h | 89 +-------------------------------------- lib/Makefile | 2 +- lib/jhash.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++ lib/rhashtable.c | 13 +++--- 4 files changed, 123 insertions(+), 94 deletions(-) create mode 100644 lib/jhash.c diff --git a/include/linux/jhash.h b/include/linux/jhash.h index 348c6f4..847c1aa 100644 --- a/include/linux/jhash.h +++ b/include/linux/jhash.h @@ -57,93 +57,8 @@ /* An arbitrary initial parameter */ #define JHASH_INITVAL 0xdeadbeef -/* jhash - hash an arbitrary key - * @k: sequence of bytes as key - * @length: the length of the key - * @initval: the previous hash, or an arbitray value - * - * The generic version, hashes an arbitrary sequence of bytes. - * No alignment or length assumptions are made about the input key. - * - * Returns the hash value of the key. The result depends on endianness. - */ -static inline u32 jhash(const void *key, u32 length, u32 initval) -{ - u32 a, b, c; - const u8 *k = key; - - /* Set up the internal state */ - a = b = c = JHASH_INITVAL + length + initval; - - /* All but the last block: affect some 32 bits of (a,b,c) */ - while (length > 12) { - a += __get_unaligned_cpu32(k); - b += __get_unaligned_cpu32(k + 4); - c += __get_unaligned_cpu32(k + 8); - __jhash_mix(a, b, c); - length -= 12; - k += 12; - } - /* Last block: affect all 32 bits of (c) */ - /* All the case statements fall through */ - switch (length) { - case 12: c += (u32)k[11]<<24; - case 11: c += (u32)k[10]<<16; - case 10: c += (u32)k[9]<<8; - case 9: c += k[8]; - case 8: b += (u32)k[7]<<24; - case 7: b += (u32)k[6]<<16; - case 6: b += (u32)k[5]<<8; - case 5: b += k[4]; - case 4: a += (u32)k[3]<<24; - case 3: a += (u32)k[2]<<16; - case 2: a += (u32)k[1]<<8; - case 1: a += k[0]; - __jhash_final(a, b, c); - case 0: /* Nothing left to add */ - break; - } - - return c; -} - -/* jhash2 - hash an array of u32's - * @k: the key which must be an array of u32's - * @length: the number of u32's in the key - * @initval: the previous hash, or an arbitray value - * - * Returns the hash value of the key. - */ -static inline u32 jhash2(const u32 *k, u32 length, u32 initval) -{ - u32 a, b, c; - - /* Set up the internal state */ - a = b = c = JHASH_INITVAL + (length<<2) + initval; - - /* Handle most of the key */ - while (length > 3) { - a += k[0]; - b += k[1]; - c += k[2]; - __jhash_mix(a, b, c); - length -= 3; - k += 3; - } - - /* Handle the last 3 u32's: all the case statements fall through */ - switch (length) { - case 3: c += k[2]; - case 2: b += k[1]; - case 1: a += k[0]; - __jhash_final(a, b, c); - case 0: /* Nothing left to add */ - break; - } - - return c; -} - +u32 jhash(const void *key, u32 length, u32 initval); +u32 jhash2(const u32 *k, u32 length, u32 initval); /* __jhash_nwords - hash exactly 3, 2 or 1 word(s) */ static inline u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval) diff --git a/lib/Makefile b/lib/Makefile index 6897b52..978be53 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -26,7 +26,7 @@ obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ gcd.o lcm.o list_sort.o uuid.o flex_array.o iov_iter.o clz_ctz.o \ bsearch.o find_bit.o llist.o memweight.o kfifo.o \ - percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o + percpu-refcount.o percpu_ida.o jhash.o rhashtable.o reciprocal_div.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o obj-y += hexdump.o diff --git a/lib/jhash.c b/lib/jhash.c new file mode 100644 index 0000000..880a7c8 --- /dev/null +++ b/lib/jhash.c @@ -0,0 +1,113 @@ +/* Jenkins hash support. + * + * Copyright (C) 2006. Bob Jenkins (bob_jenk...@burtleburtle.net) + * + * http://burtleburtle.net/bob/hash/ + * + * These are the credits from Bob's sources: + * + * lookup3.c, by Bob Jenkins, May 2006, Public Domain. + * + * These are functions for producing 32-bit hashes for hash table lookup. + * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() + * are externally useful functions. Routines to test the hash are included + * if SELF_TEST is defined. You can use this free for any purpose. It's in + * the public domain. It has no warranty. + * + * Copyright (C) 2009-2010 Jozsef Kadlecsik (kad...@blackhole.kfki.hu) + * + * I've modified Bob's hash to be useful in the Linux kernel, and + * any bugs present are my fault. + * Jozsef + */ +#include <linux/export.h> +#include <linux/jhash.h> + +/* jhash - hash an arbitrary key + * @k: sequence of bytes as key + * @length: the length of the key + * @initval: the previous hash, or an arbitray value + * + * The generic version, hashes an arbitrary sequence of bytes. + * No alignment or length assumptions are made about the input key. + * + * Returns the hash value of the key. The result depends on endianness. + */ +u32 jhash(const void *key, u32 length, u32 initval) +{ + u32 a, b, c; + const u8 *k = key; + + /* Set up the internal state */ + a = b = c = JHASH_INITVAL + length + initval; + + /* All but the last block: affect some 32 bits of (a,b,c) */ + while (length > 12) { + a += __get_unaligned_cpu32(k); + b += __get_unaligned_cpu32(k + 4); + c += __get_unaligned_cpu32(k + 8); + __jhash_mix(a, b, c); + length -= 12; + k += 12; + } + /* Last block: affect all 32 bits of (c) */ + /* All the case statements fall through */ + switch (length) { + case 12: c += (u32)k[11]<<24; + case 11: c += (u32)k[10]<<16; + case 10: c += (u32)k[9]<<8; + case 9: c += k[8]; + case 8: b += (u32)k[7]<<24; + case 7: b += (u32)k[6]<<16; + case 6: b += (u32)k[5]<<8; + case 5: b += k[4]; + case 4: a += (u32)k[3]<<24; + case 3: a += (u32)k[2]<<16; + case 2: a += (u32)k[1]<<8; + case 1: a += k[0]; + __jhash_final(a, b, c); + case 0: /* Nothing left to add */ + break; + } + + return c; +} +EXPORT_SYMBOL(jhash); + +/* jhash2 - hash an array of u32's + * @k: the key which must be an array of u32's + * @length: the number of u32's in the key + * @initval: the previous hash, or an arbitray value + * + * Returns the hash value of the key. + */ +u32 jhash2(const u32 *k, u32 length, u32 initval) +{ + u32 a, b, c; + + /* Set up the internal state */ + a = b = c = JHASH_INITVAL + (length<<2) + initval; + + /* Handle most of the key */ + while (length > 3) { + a += k[0]; + b += k[1]; + c += k[2]; + __jhash_mix(a, b, c); + length -= 3; + k += 3; + } + + /* Handle the last 3 u32's: all the case statements fall through */ + switch (length) { + case 3: c += k[2]; + case 2: b += k[1]; + case 1: a += k[0]; + __jhash_final(a, b, c); + case 0: /* Nothing left to add */ + break; + } + + return c; +} +EXPORT_SYMBOL(jhash2); diff --git a/lib/rhashtable.c b/lib/rhashtable.c index cc0c697..cf429c5 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -663,11 +663,6 @@ static size_t rounded_hashtable_size(const struct rhashtable_params *params) (unsigned long)params->min_size); } -static u32 rhashtable_jhash2(const void *key, u32 length, u32 seed) -{ - return jhash2(key, length, seed); -} - /** * rhashtable_init - initialize a new hash table * @ht: hash table to be initialized @@ -773,8 +768,14 @@ int rhashtable_init(struct rhashtable *ht, ht->p.hashfn = jhash; if (!(ht->key_len & (sizeof(u32) - 1))) { + typedef u32 (*hashfunc)(const void *k, u32 length, u32 initval); + ht->key_len /= sizeof(u32); - ht->p.hashfn = rhashtable_jhash2; + /* + * jhash2() 1st param is const u32*, + * p.hashfn wants const void*. Hence the cast: + */ + ht->p.hashfn = (hashfunc)jhash2; } } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
