diff options
| -rw-r--r-- | include/linux/crush/crush.h | 12 | ||||
| -rw-r--r-- | net/ceph/crush/crush.c | 14 | ||||
| -rw-r--r-- | net/ceph/crush/crush_ln_table.h | 166 | ||||
| -rw-r--r-- | net/ceph/crush/mapper.c | 101 | ||||
| -rw-r--r-- | net/ceph/osdmap.c | 25 |
5 files changed, 316 insertions, 2 deletions
diff --git a/include/linux/crush/crush.h b/include/linux/crush/crush.h index 4fad5f8ee01d..48a1a7d100f1 100644 --- a/include/linux/crush/crush.h +++ b/include/linux/crush/crush.h @@ -96,13 +96,15 @@ struct crush_rule { * uniform O(1) poor poor * list O(n) optimal poor * tree O(log n) good good - * straw O(n) optimal optimal + * straw O(n) better better + * straw2 O(n) optimal optimal */ enum { CRUSH_BUCKET_UNIFORM = 1, CRUSH_BUCKET_LIST = 2, CRUSH_BUCKET_TREE = 3, - CRUSH_BUCKET_STRAW = 4 + CRUSH_BUCKET_STRAW = 4, + CRUSH_BUCKET_STRAW2 = 5, }; extern const char *crush_bucket_alg_name(int alg); @@ -149,6 +151,11 @@ struct crush_bucket_straw { __u32 *straws; /* 16-bit fixed point */ }; +struct crush_bucket_straw2 { + struct crush_bucket h; + __u32 *item_weights; /* 16-bit fixed point */ +}; + /* @@ -189,6 +196,7 @@ extern void crush_destroy_bucket_uniform(struct crush_bucket_uniform *b); extern void crush_destroy_bucket_list(struct crush_bucket_list *b); extern void crush_destroy_bucket_tree(struct crush_bucket_tree *b); extern void crush_destroy_bucket_straw(struct crush_bucket_straw *b); +extern void crush_destroy_bucket_straw2(struct crush_bucket_straw2 *b); extern void crush_destroy_bucket(struct crush_bucket *b); extern void crush_destroy_rule(struct crush_rule *r); extern void crush_destroy(struct crush_map *map); diff --git a/net/ceph/crush/crush.c b/net/ceph/crush/crush.c index 16bc199d9a62..9d84ce4ea0df 100644 --- a/net/ceph/crush/crush.c +++ b/net/ceph/crush/crush.c @@ -17,6 +17,7 @@ const char *crush_bucket_alg_name(int alg) case CRUSH_BUCKET_LIST: return "list"; case CRUSH_BUCKET_TREE: return "tree"; case CRUSH_BUCKET_STRAW: return "straw"; + case CRUSH_BUCKET_STRAW2: return "straw2"; default: return "unknown"; } } @@ -40,6 +41,8 @@ int crush_get_bucket_item_weight(const struct crush_bucket *b, int p) return ((struct crush_bucket_tree *)b)->node_weights[crush_calc_tree_node(p)]; case CRUSH_BUCKET_STRAW: return ((struct crush_bucket_straw *)b)->item_weights[p]; + case CRUSH_BUCKET_STRAW2: + return ((struct crush_bucket_straw2 *)b)->item_weights[p]; } return 0; } @@ -77,6 +80,14 @@ void crush_destroy_bucket_straw(struct crush_bucket_straw *b) kfree(b); } +void crush_destroy_bucket_straw2(struct crush_bucket_straw2 *b) +{ + kfree(b->item_weights); + kfree(b->h.perm); + kfree(b->h.items); + kfree(b); +} + void crush_destroy_bucket(struct crush_bucket *b) { switch (b->alg) { @@ -92,6 +103,9 @@ void crush_destroy_bucket(struct crush_bucket *b) case CRUSH_BUCKET_STRAW: crush_destroy_bucket_straw((struct crush_bucket_straw *)b); break; + case CRUSH_BUCKET_STRAW2: + crush_destroy_bucket_straw2((struct crush_bucket_straw2 *)b); + break; } } diff --git a/net/ceph/crush/crush_ln_table.h b/net/ceph/crush/crush_ln_table.h new file mode 100644 index 000000000000..6192c7fc958c --- /dev/null +++ b/net/ceph/crush/crush_ln_table.h @@ -0,0 +1,166 @@ +/* + * Ceph - scalable distributed file system + * + * Copyright (C) 2015 Intel Corporation All Rights Reserved + * + * This is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software + * Foundation. See file COPYING. + * + */ + +#if defined(__linux__) +#include <linux/types.h> +#elif defined(__FreeBSD__) +#include <sys/types.h> +#endif + +#ifndef CEPH_CRUSH_LN_H +#define CEPH_CRUSH_LN_H + + +// RH_LH_tbl[2*k] = 2^48/(1.0+k/128.0) +// RH_LH_tbl[2*k+1] = 2^48*log2(1.0+k/128.0) + +static int64_t __RH_LH_tbl[128*2+2] = { + 0x0001000000000000ll, 0x0000000000000000ll, 0x0000fe03f80fe040ll, 0x000002dfca16dde1ll, + 0x0000fc0fc0fc0fc1ll, 0x000005b9e5a170b4ll, 0x0000fa232cf25214ll, 0x0000088e68ea899all, + 0x0000f83e0f83e0f9ll, 0x00000b5d69bac77ell, 0x0000f6603d980f67ll, 0x00000e26fd5c8555ll, + 0x0000f4898d5f85bcll, 0x000010eb389fa29fll, 0x0000f2b9d6480f2cll, 0x000013aa2fdd27f1ll, + 0x0000f0f0f0f0f0f1ll, 0x00001663f6fac913ll, 0x0000ef2eb71fc435ll, 0x00001918a16e4633ll, + 0x0000ed7303b5cc0fll, 0x00001bc84240adabll, 0x0000ebbdb2a5c162ll, 0x00001e72ec117fa5ll, + 0x0000ea0ea0ea0ea1ll, 0x00002118b119b4f3ll, 0x0000e865ac7b7604ll, 0x000023b9a32eaa56ll, + 0x0000e6c2b4481cd9ll, 0x00002655d3c4f15cll, 0x0000e525982af70dll, 0x000028ed53f307eell, + 0x0000e38e38e38e39ll, 0x00002b803473f7adll, 0x0000e1fc780e1fc8ll, 0x00002e0e85a9de04ll, + 0x0000e070381c0e08ll, 0x0000309857a05e07ll, 0x0000dee95c4ca038ll, 0x0000331dba0efce1ll, + 0x0000dd67c8a60dd7ll, 0x0000359ebc5b69d9ll, 0x0000dbeb61eed19dll, 0x0000381b6d9bb29bll, + 0x0000da740da740dbll, 0x00003a93dc9864b2ll, 0x0000d901b2036407ll, 0x00003d0817ce9cd4ll, + 0x0000d79435e50d7all, 0x00003f782d7204d0ll, 0x0000d62b80d62b81ll, 0x000041e42b6ec0c0ll, + 0x0000d4c77b03531ell, 0x0000444c1f6b4c2dll, 0x0000d3680d3680d4ll, 0x000046b016ca47c1ll, + 0x0000d20d20d20d21ll, 0x000049101eac381cll, 0x0000d0b69fcbd259ll, 0x00004b6c43f1366all, + 0x0000cf6474a8819fll, 0x00004dc4933a9337ll, 0x0000ce168a772509ll, 0x0000501918ec6c11ll, + 0x0000cccccccccccdll, 0x00005269e12f346ell, 0x0000cb8727c065c4ll, 0x000054b6f7f1325all, + 0x0000ca4587e6b750ll, 0x0000570068e7ef5all, 0x0000c907da4e8712ll, 0x000059463f919deell, + 0x0000c7ce0c7ce0c8ll, 0x00005b8887367433ll, 0x0000c6980c6980c7ll, 0x00005dc74ae9fbecll, + 0x0000c565c87b5f9ell, 0x00006002958c5871ll, 0x0000c4372f855d83ll, 0x0000623a71cb82c8ll, + 0x0000c30c30c30c31ll, 0x0000646eea247c5cll, 0x0000c1e4bbd595f7ll, 0x000066a008e4788cll, + 0x0000c0c0c0c0c0c1ll, 0x000068cdd829fd81ll, 0x0000bfa02fe80bfbll, 0x00006af861e5fc7dll, + 0x0000be82fa0be830ll, 0x00006d1fafdce20all, 0x0000bd6910470767ll, 0x00006f43cba79e40ll, + 0x0000bc52640bc527ll, 0x00007164beb4a56dll, 0x0000bb3ee721a54ell, 0x000073829248e961ll, + 0x0000ba2e8ba2e8bbll, 0x0000759d4f80cba8ll, 0x0000b92143fa36f6ll, 0x000077b4ff5108d9ll, + 0x0000b81702e05c0cll, 0x000079c9aa879d53ll, 0x0000b70fbb5a19bfll, 0x00007bdb59cca388ll, + 0x0000b60b60b60b61ll, 0x00007dea15a32c1bll, 0x0000b509e68a9b95ll, 0x00007ff5e66a0ffell, + 0x0000b40b40b40b41ll, 0x000081fed45cbccbll, 0x0000b30f63528918ll, 0x00008404e793fb81ll, + 0x0000b21642c8590cll, 0x000086082806b1d5ll, 0x0000b11fd3b80b12ll, 0x000088089d8a9e47ll, + 0x0000b02c0b02c0b1ll, 0x00008a064fd50f2all, 0x0000af3addc680b0ll, 0x00008c01467b94bbll, + 0x0000ae4c415c9883ll, 0x00008df988f4ae80ll, 0x0000ad602b580ad7ll, 0x00008fef1e987409ll, + 0x0000ac7691840ac8ll, 0x000091e20ea1393ell, 0x0000ab8f69e2835all, 0x000093d2602c2e5fll, + 0x0000aaaaaaaaaaabll, 0x000095c01a39fbd6ll, 0x0000a9c84a47a080ll, 0x000097ab43af59f9ll, + 0x0000a8e83f5717c1ll, 0x00009993e355a4e5ll, 0x0000a80a80a80a81ll, 0x00009b79ffdb6c8bll, + 0x0000a72f0539782all, 0x00009d5d9fd5010bll, 0x0000a655c4392d7cll, 0x00009f3ec9bcfb80ll, + 0x0000a57eb50295fbll, 0x0000a11d83f4c355ll, 0x0000a4a9cf1d9684ll, 0x0000a2f9d4c51039ll, + 0x0000a3d70a3d70a4ll, 0x0000a4d3c25e68dcll, 0x0000a3065e3fae7dll, 0x0000a6ab52d99e76ll, + 0x0000a237c32b16d0ll, 0x0000a8808c384547ll, 0x0000a16b312ea8fdll, 0x0000aa5374652a1cll, + 0x0000a0a0a0a0a0a1ll, 0x0000ac241134c4e9ll, 0x00009fd809fd80a0ll, 0x0000adf26865a8a1ll, + 0x00009f1165e72549ll, 0x0000afbe7fa0f04dll, 0x00009e4cad23dd60ll, 0x0000b1885c7aa982ll, + 0x00009d89d89d89d9ll, 0x0000b35004723c46ll, 0x00009cc8e160c3fcll, 0x0000b5157cf2d078ll, + 0x00009c09c09c09c1ll, 0x0000b6d8cb53b0call, 0x00009b4c6f9ef03bll, 0x0000b899f4d8ab63ll, + 0x00009a90e7d95bc7ll, 0x0000ba58feb2703all, 0x000099d722dabde6ll, 0x0000bc15edfeed32ll, + 0x0000991f1a515886ll, 0x0000bdd0c7c9a817ll, 0x00009868c809868dll, 0x0000bf89910c1678ll, + 0x000097b425ed097cll, 0x0000c1404eadf383ll, 0x000097012e025c05ll, 0x0000c2f5058593d9ll, + 0x0000964fda6c0965ll, 0x0000c4a7ba58377cll, 0x000095a02568095bll, 0x0000c65871da59ddll, + 0x000094f2094f2095ll, 0x0000c80730b00016ll, 0x0000944580944581ll, 0x0000c9b3fb6d0559ll, + 0x0000939a85c4093all, 0x0000cb5ed69565afll, 0x000092f113840498ll, 0x0000cd07c69d8702ll, + 0x0000924924924925ll, 0x0000ceaecfea8085ll, 0x000091a2b3c4d5e7ll, 0x0000d053f6d26089ll, + 0x000090fdbc090fdcll, 0x0000d1f73f9c70c0ll, 0x0000905a38633e07ll, 0x0000d398ae817906ll, + 0x00008fb823ee08fcll, 0x0000d53847ac00a6ll, 0x00008f1779d9fdc4ll, 0x0000d6d60f388e41ll, + 0x00008e78356d1409ll, 0x0000d8720935e643ll, 0x00008dda5202376all, 0x0000da0c39a54804ll, + 0x00008d3dcb08d3ddll, 0x0000dba4a47aa996ll, 0x00008ca29c046515ll, 0x0000dd3b4d9cf24bll, + 0x00008c08c08c08c1ll, 0x0000ded038e633f3ll, 0x00008b70344a139cll, 0x0000e0636a23e2eell, + 0x00008ad8f2fba939ll, 0x0000e1f4e5170d02ll, 0x00008a42f870566all, 0x0000e384ad748f0ell, + 0x000089ae4089ae41ll, 0x0000e512c6e54998ll, 0x0000891ac73ae982ll, 0x0000e69f35065448ll, + 0x0000888888888889ll, 0x0000e829fb693044ll, 0x000087f78087f781ll, 0x0000e9b31d93f98ell, + 0x00008767ab5f34e5ll, 0x0000eb3a9f019750ll, 0x000086d905447a35ll, 0x0000ecc08321eb30ll, + 0x0000864b8a7de6d2ll, 0x0000ee44cd59ffabll, 0x000085bf37612cefll, 0x0000efc781043579ll, + 0x0000853408534086ll, 0x0000f148a170700all, 0x000084a9f9c8084bll, 0x0000f2c831e44116ll, + 0x0000842108421085ll, 0x0000f446359b1353ll, 0x0000839930523fbfll, 0x0000f5c2afc65447ll, + 0x000083126e978d50ll, 0x0000f73da38d9d4all, 0x0000828cbfbeb9a1ll, 0x0000f8b7140edbb1ll, + 0x0000820820820821ll, 0x0000fa2f045e7832ll, 0x000081848da8faf1ll, 0x0000fba577877d7dll, + 0x0000810204081021ll, 0x0000fd1a708bbe11ll, 0x0000808080808081ll, 0x0000fe8df263f957ll, + 0x0000800000000000ll, 0x0000ffff00000000ll, + }; + + + // LL_tbl[k] = 2^48*log2(1.0+k/2^15); +static int64_t __LL_tbl[256] = { + 0x0000000000000000ull, 0x00000002e2a60a00ull, 0x000000070cb64ec5ull, 0x00000009ef50ce67ull, + 0x0000000cd1e588fdull, 0x0000000fb4747e9cull, 0x0000001296fdaf5eull, 0x0000001579811b58ull, + 0x000000185bfec2a1ull, 0x0000001b3e76a552ull, 0x0000001e20e8c380ull, 0x0000002103551d43ull, + 0x00000023e5bbb2b2ull, 0x00000026c81c83e4ull, 0x00000029aa7790f0ull, 0x0000002c8cccd9edull, + 0x0000002f6f1c5ef2ull, 0x0000003251662017ull, 0x0000003533aa1d71ull, 0x0000003815e8571aull, + 0x0000003af820cd26ull, 0x0000003dda537faeull, 0x00000040bc806ec8ull, 0x000000439ea79a8cull, + 0x0000004680c90310ull, 0x0000004962e4a86cull, 0x0000004c44fa8ab6ull, 0x0000004f270aaa06ull, + 0x0000005209150672ull, 0x00000054eb19a013ull, 0x00000057cd1876fdull, 0x0000005aaf118b4aull, + 0x0000005d9104dd0full, 0x0000006072f26c64ull, 0x0000006354da3960ull, 0x0000006636bc441aull, + 0x0000006918988ca8ull, 0x0000006bfa6f1322ull, 0x0000006edc3fd79full, 0x00000071be0ada35ull, + 0x000000749fd01afdull, 0x00000077818f9a0cull, 0x0000007a6349577aull, 0x0000007d44fd535eull, + 0x0000008026ab8dceull, 0x00000083085406e3ull, 0x00000085e9f6beb2ull, 0x00000088cb93b552ull, + 0x0000008bad2aeadcull, 0x0000008e8ebc5f65ull, 0x0000009170481305ull, 0x0000009451ce05d3ull, + 0x00000097334e37e5ull, 0x0000009a14c8a953ull, 0x0000009cf63d5a33ull, 0x0000009fd7ac4a9dull, + 0x000000a2b07f3458ull, 0x000000a59a78ea6aull, 0x000000a87bd699fbull, 0x000000ab5d2e8970ull, + 0x000000ae3e80b8e3ull, 0x000000b11fcd2869ull, 0x000000b40113d818ull, 0x000000b6e254c80aull, + 0x000000b9c38ff853ull, 0x000000bca4c5690cull, 0x000000bf85f51a4aull, 0x000000c2671f0c26ull, + 0x000000c548433eb6ull, 0x000000c82961b211ull, 0x000000cb0a7a664dull, 0x000000cdeb8d5b82ull, + 0x000000d0cc9a91c8ull, 0x000000d3ada20933ull, 0x000000d68ea3c1ddull, 0x000000d96f9fbbdbull, + 0x000000dc5095f744ull, 0x000000df31867430ull, 0x000000e2127132b5ull, 0x000000e4f35632eaull, + 0x000000e7d43574e6ull, 0x000000eab50ef8c1ull, 0x000000ed95e2be90ull, 0x000000f076b0c66cull, + 0x000000f35779106aull, 0x000000f6383b9ca2ull, 0x000000f918f86b2aull, 0x000000fbf9af7c1aull, + 0x000000feda60cf88ull, 0x00000101bb0c658cull, 0x000001049bb23e3cull, 0x000001077c5259afull, + 0x0000010a5cecb7fcull, 0x0000010d3d81593aull, 0x000001101e103d7full, 0x00000112fe9964e4ull, + 0x00000115df1ccf7eull, 0x00000118bf9a7d64ull, 0x0000011ba0126eadull, 0x0000011e8084a371ull, + 0x0000012160f11bc6ull, 0x000001244157d7c3ull, 0x0000012721b8d77full, 0x0000012a02141b10ull, + 0x0000012ce269a28eull, 0x0000012fc2b96e0full, 0x00000132a3037daaull, 0x000001358347d177ull, + 0x000001386386698cull, 0x0000013b43bf45ffull, 0x0000013e23f266e9ull, 0x00000141041fcc5eull, + 0x00000143e4477678ull, 0x00000146c469654bull, 0x00000149a48598f0ull, 0x0000014c849c117cull, + 0x0000014f64accf08ull, 0x0000015244b7d1a9ull, 0x0000015524bd1976ull, 0x0000015804bca687ull, + 0x0000015ae4b678f2ull, 0x0000015dc4aa90ceull, 0x00000160a498ee31ull, 0x0000016384819134ull, + 0x00000166646479ecull, 0x000001694441a870ull, 0x0000016c24191cd7ull, 0x0000016df6ca19bdull, + 0x00000171e3b6d7aaull, 0x00000174c37d1e44ull, 0x00000177a33dab1cull, 0x0000017a82f87e49ull, + 0x0000017d62ad97e2ull, 0x00000180425cf7feull, 0x00000182b07f3458ull, 0x0000018601aa8c19ull, + 0x00000188e148c046ull, 0x0000018bc0e13b52ull, 0x0000018ea073fd52ull, 0x000001918001065dull, + 0x000001945f88568bull, 0x000001973f09edf2ull, 0x0000019a1e85ccaaull, 0x0000019cfdfbf2c8ull, + 0x0000019fdd6c6063ull, 0x000001a2bcd71593ull, 0x000001a59c3c126eull, 0x000001a87b9b570bull, + 0x000001ab5af4e380ull, 0x000001ae3a48b7e5ull, 0x000001b11996d450ull, 0x000001b3f8df38d9ull, + 0x000001b6d821e595ull, 0x000001b9b75eda9bull, 0x000001bc96961803ull, 0x000001bf75c79de3ull, + 0x000001c254f36c51ull, 0x000001c534198365ull, 0x000001c81339e336ull, 0x000001caf2548bd9ull, + 0x000001cdd1697d67ull, 0x000001d0b078b7f5ull, 0x000001d38f823b9aull, 0x000001d66e86086dull, + 0x000001d94d841e86ull, 0x000001dc2c7c7df9ull, 0x000001df0b6f26dfull, 0x000001e1ea5c194eull, + 0x000001e4c943555dull, 0x000001e7a824db23ull, 0x000001ea8700aab5ull, 0x000001ed65d6c42bull, + 0x000001f044a7279dull, 0x000001f32371d51full, 0x000001f60236cccaull, 0x000001f8e0f60eb3ull, + 0x000001fbbfaf9af3ull, 0x000001fe9e63719eull, 0x000002017d1192ccull, 0x000002045bb9fe94ull, + 0x000002073a5cb50dull, 0x00000209c06e6212ull, 0x0000020cf791026aull, 0x0000020fd622997cull, + 0x00000212b07f3458ull, 0x000002159334a8d8ull, 0x0000021871b52150ull, 0x0000021b502fe517ull, + 0x0000021d6a73a78full, 0x000002210d144eeeull, 0x00000223eb7df52cull, 0x00000226c9e1e713ull, + 0x00000229a84024bbull, 0x0000022c23679b4eull, 0x0000022f64eb83a8ull, 0x000002324338a51bull, + 0x00000235218012a9ull, 0x00000237ffc1cc69ull, 0x0000023a2c3b0ea4ull, 0x0000023d13ee805bull, + 0x0000024035e9221full, 0x00000243788faf25ull, 0x0000024656b4e735ull, 0x00000247ed646bfeull, + 0x0000024c12ee3d98ull, 0x0000024ef1025c1aull, 0x00000251cf10c799ull, 0x0000025492644d65ull, + 0x000002578b1c85eeull, 0x0000025a6919d8f0ull, 0x0000025d13ee805bull, 0x0000026025036716ull, + 0x0000026296453882ull, 0x00000265e0d62b53ull, 0x00000268beb701f3ull, 0x0000026b9c92265eull, + 0x0000026d32f798a9ull, 0x00000271583758ebull, 0x000002743601673bull, 0x0000027713c5c3b0ull, + 0x00000279f1846e5full, 0x0000027ccf3d6761ull, 0x0000027e6580aecbull, 0x000002828a9e44b3ull, + 0x0000028568462932ull, 0x00000287bdbf5255ull, 0x0000028b2384de4aull, 0x0000028d13ee805bull, + 0x0000029035e9221full, 0x0000029296453882ull, 0x0000029699bdfb61ull, 0x0000029902a37aabull, + 0x0000029c54b864c9ull, 0x0000029deabd1083ull, 0x000002a20f9c0bb5ull, 0x000002a4c7605d61ull, + 0x000002a7bdbf5255ull, 0x000002a96056dafcull, 0x000002ac3daf14efull, 0x000002af1b019ecaull, + 0x000002b296453882ull, 0x000002b5d022d80full, 0x000002b8fa471cb3ull, 0x000002ba9012e713ull, + 0x000002bd6d4901ccull, 0x000002c04a796cf6ull, 0x000002c327a428a6ull, 0x000002c61a5e8f4cull, + 0x000002c8e1e891f6ull, 0x000002cbbf023fc2ull, 0x000002ce9c163e6eull, 0x000002d179248e13ull, + 0x000002d4562d2ec6ull, 0x000002d73330209dull, 0x000002da102d63b0ull, 0x000002dced24f814ull, +}; + + + + +#endif diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c index 91c41fe83113..5b47736d27d9 100644 --- a/net/ceph/crush/mapper.c +++ b/net/ceph/crush/mapper.c @@ -20,6 +20,7 @@ #include <linux/crush/crush.h> #include <linux/crush/hash.h> +#include "crush_ln_table.h" /* * Implement the core CRUSH mapping algorithm. @@ -237,6 +238,102 @@ static int bucket_straw_choose(struct crush_bucket_straw *bucket, return bucket->h.items[high]; } +// compute 2^44*log2(input+1) +uint64_t crush_ln(unsigned xin) +{ + unsigned x=xin, x1; + int iexpon, index1, index2; + uint64_t RH, LH, LL, xl64, result; + + x++; + + // normalize input + iexpon = 15; + while(!(x&0x18000)) { x<<=1; iexpon--; } + + index1 = (x>>8)<<1; + // RH ~ 2^56/index1 + RH = __RH_LH_tbl[index1 - 256]; + // LH ~ 2^48 * log2(index1/256) + LH = __RH_LH_tbl[index1 + 1 - 256]; + + // RH*x ~ 2^48 * (2^15 + xf), xf<2^8 + xl64 = (int64_t)x * RH; + xl64 >>= 48; + x1 = xl64; + + result = iexpon; + result <<= (12 + 32); + + index2 = x1 & 0xff; + // LL ~ 2^48*log2(1.0+index2/2^15) + LL = __LL_tbl[index2]; + + LH = LH + LL; + + LH >>= (48-12 - 32); + result += LH; + + return result; +} + + +/* + * straw2 + * + * for reference, see: + * + * http://en.wikipedia.org/wiki/Exponential_distribution#Distribution_of_the_minimum_of_exponential_random_variables + * + */ + +static int bucket_straw2_choose(struct crush_bucket_straw2 *bucket, + int x, int r) +{ + unsigned i, high = 0; + unsigned u; + unsigned w; + __s64 ln, draw, high_draw = 0; + + for (i = 0; i < bucket->h.size; i++) { + w = bucket->item_weights[i]; + if (w) { + u = crush_hash32_3(bucket->h.hash, x, + bucket->h.items[i], r); + u &= 0xffff; + + /* + * for some reason slightly less than 0x10000 produces + * a slightly more accurate distribution... probably a + * rounding effect. + * + * the natural log lookup table maps [0,0xffff] + * (corresponding to real numbers [1/0x10000, 1] to + * [0, 0xffffffffffff] (corresponding to real numbers + * [-11.090355,0]). + */ + ln = crush_ln(u) - 0x1000000000000ll; + + /* + * divide by 16.16 fixed-point weight. note + * that the ln value is negative, so a larger + * weight means a larger (less negative) value + * for draw. + */ + draw = div64_s64(ln, w); + } else { + draw = S64_MIN; + } + + if (i == 0 || draw > high_draw) { + high = i; + high_draw = draw; + } + } + return bucket->h.items[high]; +} + + static int crush_bucket_choose(struct crush_bucket *in, int x, int r) { dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r); @@ -254,12 +351,16 @@ static int crush_bucket_choose(struct crush_bucket *in, int x, int r) case CRUSH_BUCKET_STRAW: return bucket_straw_choose((struct crush_bucket_straw *)in, x, r); + case CRUSH_BUCKET_STRAW2: + return bucket_straw2_choose((struct crush_bucket_straw2 *)in, + x, r); default: dprintk("unknown bucket %d alg %d\n", in->id, in->alg); return in->items[0]; } } + /* * true if device is marked "out" (failed, fully offloaded) * of the cluster diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index b8c3fde5b04f..15796696d64e 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -122,6 +122,22 @@ bad: return -EINVAL; } +static int crush_decode_straw2_bucket(void **p, void *end, + struct crush_bucket_straw2 *b) +{ + int j; + dout("crush_decode_straw2_bucket %p to %p\n", *p, end); + b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS); + if (b->item_weights == NULL) + return -ENOMEM; + ceph_decode_need(p, end, b->h.size * sizeof(u32), bad); + for (j = 0; j < b->h.size; j++) + b->item_weights[j] = ceph_decode_32(p); + return 0; +bad: + return -EINVAL; +} + static int skip_name_map(void **p, void *end) { int len; @@ -204,6 +220,9 @@ static struct crush_map *crush_decode(void *pbyval, void *end) case CRUSH_BUCKET_STRAW: size = sizeof(struct crush_bucket_straw); break; + case CRUSH_BUCKET_STRAW2: + size = sizeof(struct crush_bucket_straw2); + break; default: err = -EINVAL; goto bad; @@ -261,6 +280,12 @@ static struct crush_map *crush_decode(void *pbyval, void *end) if (err < 0) goto bad; break; + case CRUSH_BUCKET_STRAW2: + err = crush_decode_straw2_bucket(p, end, + (struct crush_bucket_straw2 *)b); + if (err < 0) + goto bad; + break; } } |