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author | Alex Gorrod <alexg@wiredtiger.com> | 2015-10-29 12:07:10 +1100 |
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committer | Alex Gorrod <alexg@wiredtiger.com> | 2015-10-29 12:07:10 +1100 |
commit | 8323d282dd3fec6a378050ad7ee3a2543db03446 (patch) | |
tree | 2d8ffbfc800b62805c3f3eb552b27229aba8dcc7 | |
parent | c9e91b66f589c55b7d49cca47070a268b218a9aa (diff) | |
parent | 35d46c3a0e7b4c87849df7283544d2e6208d5edd (diff) | |
download | mongo-8323d282dd3fec6a378050ad7ee3a2543db03446.tar.gz |
Merge branch 'develop' into inmem
-rw-r--r-- | dist/flags.py | 1 | ||||
-rw-r--r-- | src/btree/bt_delete.c | 10 | ||||
-rw-r--r-- | src/btree/bt_read.c | 6 | ||||
-rw-r--r-- | src/btree/bt_split.c | 40 | ||||
-rw-r--r-- | src/btree/bt_walk.c | 14 | ||||
-rw-r--r-- | src/evict/evict_page.c | 37 | ||||
-rw-r--r-- | src/include/btmem.h | 1 | ||||
-rw-r--r-- | src/include/btree.i | 10 | ||||
-rw-r--r-- | src/include/extern.h | 3 | ||||
-rw-r--r-- | src/include/flags.h | 15 |
10 files changed, 108 insertions, 29 deletions
diff --git a/dist/flags.py b/dist/flags.py index 4a6bd272109..da677c17389 100644 --- a/dist/flags.py +++ b/dist/flags.py @@ -36,6 +36,7 @@ flags = { 'page_read' : [ 'READ_CACHE', 'READ_COMPACT', + 'READ_NO_EMPTY', 'READ_NO_EVICT', 'READ_NO_GEN', 'READ_NO_WAIT', diff --git a/src/btree/bt_delete.c b/src/btree/bt_delete.c index 23429121e98..757b7b51cdd 100644 --- a/src/btree/bt_delete.c +++ b/src/btree/bt_delete.c @@ -214,10 +214,11 @@ __wt_delete_page_rollback(WT_SESSION_IMPL *session, WT_REF *ref) /* * __wt_delete_page_skip -- - * If iterating a cursor, skip deleted pages that are visible to us. + * If iterating a cursor, skip deleted pages that are either visible to + * us or globally visible. */ bool -__wt_delete_page_skip(WT_SESSION_IMPL *session, WT_REF *ref) +__wt_delete_page_skip(WT_SESSION_IMPL *session, WT_REF *ref, bool visible_all) { bool skip; @@ -245,8 +246,9 @@ __wt_delete_page_skip(WT_SESSION_IMPL *session, WT_REF *ref) if (!__wt_atomic_casv32(&ref->state, WT_REF_DELETED, WT_REF_LOCKED)) return (false); - skip = ref->page_del == NULL || - __wt_txn_visible(session, ref->page_del->txnid); + skip = ref->page_del == NULL || (visible_all ? + __wt_txn_visible_all(session, ref->page_del->txnid) : + __wt_txn_visible(session, ref->page_del->txnid)); WT_PUBLISH(ref->state, WT_REF_DELETED); return (skip); diff --git a/src/btree/bt_read.c b/src/btree/bt_read.c index d9cdfc78c75..e60f7b3fb02 100644 --- a/src/btree/bt_read.c +++ b/src/btree/bt_read.c @@ -448,8 +448,12 @@ __wt_page_in_func(WT_SESSION_IMPL *session, WT_REF *ref, uint32_t flags for (oldgen = stalled = false, force_attempts = 0, sleep_cnt = wait_cnt = 0;;) { switch (ref->state) { - case WT_REF_DISK: case WT_REF_DELETED: + if (LF_ISSET(WT_READ_NO_EMPTY) && + __wt_delete_page_skip(session, ref, false)) + return (WT_NOTFOUND); + /* FALLTHROUGH */ + case WT_REF_DISK: if (LF_ISSET(WT_READ_CACHE)) return (WT_NOTFOUND); diff --git a/src/btree/bt_split.c b/src/btree/bt_split.c index 6b3a0f339aa..66f315702b1 100644 --- a/src/btree/bt_split.c +++ b/src/btree/bt_split.c @@ -1012,11 +1012,12 @@ __split_parent(WT_SESSION_IMPL *session, WT_REF *ref, * reading thread will restart. Include the ref we are splitting in * the count to be deleted. */ - for (i = 0, deleted_entries = 1; i < parent_entries; ++i) { + deleted_entries = ref_new != NULL ? 1 : 0; + for (i = 0; i < parent_entries; ++i) { next_ref = pindex->index[i]; WT_ASSERT(session, next_ref->state != WT_REF_SPLIT); if (next_ref->state == WT_REF_DELETED && - __wt_delete_page_skip(session, next_ref) && + __wt_delete_page_skip(session, next_ref, true) && __wt_atomic_casv32( &next_ref->state, WT_REF_DELETED, WT_REF_SPLIT)) deleted_entries++; @@ -1029,6 +1030,18 @@ __split_parent(WT_SESSION_IMPL *session, WT_REF *ref, result_entries = (parent_entries + new_entries) - deleted_entries; /* + * If the entire (sub)tree is empty, leave the first ref in place, + * deleted. + */ + if (result_entries == 0) { + next_ref = pindex->index[0]; + WT_ASSERT(session, next_ref->state == WT_REF_SPLIT); + next_ref->state = WT_REF_DELETED; + --deleted_entries; + result_entries = 1; + } + + /* * Allocate and initialize a new page index array for the parent, then * copy references from the original index array, plus references from * the newly created split array, into place. @@ -1510,6 +1523,29 @@ __wt_split_insert(WT_SESSION_IMPL *session, WT_REF *ref) } /* + * __wt_split_reverse -- + * Lock, then reverse split an internal page (remove deleted refs). + */ +int +__wt_split_reverse(WT_SESSION_IMPL *session, WT_REF *ref) +{ + WT_DECL_RET; + WT_PAGE *parent; + WT_REF dummy_child; + bool hazard; + + WT_CLEAR(dummy_child); + dummy_child.home = dummy_child.page = ref->page; + dummy_child.state = WT_REF_MEM; + + WT_RET(__split_parent_lock(session, &dummy_child, &parent, &hazard)); + WT_ASSERT(session, parent == ref->page); + ret = __split_parent(session, &dummy_child, NULL, 0, 0, 0); + WT_TRET(__split_parent_unlock(session, parent, hazard)); + return (ret); +} + +/* * __wt_split_rewrite -- * Rewrite an in-memory page with a new version. */ diff --git a/src/btree/bt_walk.c b/src/btree/bt_walk.c index 6e1d182ed0b..8e0f4036b79 100644 --- a/src/btree/bt_walk.c +++ b/src/btree/bt_walk.c @@ -94,6 +94,9 @@ __wt_tree_walk(WT_SESSION_IMPL *session, */ WT_ENTER_PAGE_INDEX(session); + /* Walk should never instantiate deleted pages. */ + LF_SET(WT_READ_NO_EMPTY); + /* * !!! * Fast-truncate currently only works on row-store trees. @@ -174,9 +177,10 @@ ascend: /* /* * If we got all the way through an internal page and - * all of the child pages were deleted, evict it. + * all of the child pages were deleted, mark it for + * eviction. */ - if (empty_internal) { + if (empty_internal && pindex->entries > 1) { __wt_page_evict_soon(ref->page); empty_internal = false; } @@ -257,7 +261,7 @@ ascend: /* * to delete it again. */ if (ref->state == WT_REF_DELETED && - __wt_delete_page_skip(session, ref)) + __wt_delete_page_skip(session, ref, false)) break; /* * If deleting a range, try to delete the page @@ -294,7 +298,7 @@ ascend: /* * Try to skip deleted pages visible to us. */ if (ref->state == WT_REF_DELETED && - __wt_delete_page_skip(session, ref)) + __wt_delete_page_skip(session, ref, false)) break; } @@ -302,7 +306,7 @@ ascend: /* /* * Not-found is an expected return when only walking - * in-cache pages. + * in-cache pages, or if we see a deleted page. */ if (ret == WT_NOTFOUND) { ret = 0; diff --git a/src/evict/evict_page.c b/src/evict/evict_page.c index 3b39e1bdd2c..28c79b9b367 100644 --- a/src/evict/evict_page.c +++ b/src/evict/evict_page.c @@ -143,6 +143,28 @@ done: if (((inmem_split && ret == 0) || (forced_eviction && ret == EBUSY)) && return (ret); } +/* + * __evict_reverse_split_check -- + * Check if an internal page needs a reverse split. + */ +static int +__evict_reverse_split_check(WT_SESSION_IMPL *session, WT_REF *ref) +{ + WT_PAGE *parent; + WT_PAGE_INDEX *pindex; + uint32_t deleted_entries; + + if (__wt_ref_is_root(ref)) + return (0); + + parent = ref->home; + WT_INTL_INDEX_GET(session, parent, pindex); + deleted_entries = __wt_atomic_addv32(&pindex->deleted_entries, 1); + if (deleted_entries > pindex->entries / 10) + WT_RET(__wt_split_reverse(session, parent->pg_intl_parent_ref)); + + return (0); +} /* * __wt_evict_page_clean_update -- @@ -152,6 +174,8 @@ int __wt_evict_page_clean_update( WT_SESSION_IMPL *session, WT_REF *ref, bool closing) { + WT_DECL_RET; + /* * If doing normal system eviction, but only in the service of reducing * the number of dirty pages, leave the clean page in cache. @@ -165,8 +189,13 @@ __wt_evict_page_clean_update( * page re-instantiated (for example, by searching) and never written. */ __wt_ref_out(session, ref); - WT_PUBLISH(ref->state, - ref->addr == NULL ? WT_REF_DELETED : WT_REF_DISK); + if (ref->addr == NULL) { + WT_PUBLISH(ref->state, WT_REF_DELETED); + WT_WITH_PAGE_INDEX(session, + ret = __evict_reverse_split_check(session, ref)); + WT_RET_BUSY_OK(ret); + } else + WT_PUBLISH(ref->state, WT_REF_DISK); return (0); } @@ -179,6 +208,7 @@ static int __evict_page_dirty_update(WT_SESSION_IMPL *session, WT_REF *ref, bool closing) { WT_ADDR *addr; + WT_DECL_RET; WT_PAGE *parent; WT_PAGE_MODIFY *mod; @@ -208,6 +238,9 @@ __evict_page_dirty_update(WT_SESSION_IMPL *session, WT_REF *ref, bool closing) __wt_ref_out(session, ref); ref->addr = NULL; WT_PUBLISH(ref->state, WT_REF_DELETED); + WT_WITH_PAGE_INDEX(session, + ret = __evict_reverse_split_check(session, ref)); + WT_RET_BUSY_OK(ret); break; case WT_PM_REC_MULTIBLOCK: /* Multiple blocks */ /* diff --git a/src/include/btmem.h b/src/include/btmem.h index 2f15a452568..f4906c5f8d8 100644 --- a/src/include/btmem.h +++ b/src/include/btmem.h @@ -432,6 +432,7 @@ struct __wt_page { struct __wt_page_index { uint32_t entries; + uint32_t deleted_entries; WT_REF **index; } * volatile __index; /* Collated children */ diff --git a/src/include/btree.i b/src/include/btree.i index 3103f028eeb..23e212eb772 100644 --- a/src/include/btree.i +++ b/src/include/btree.i @@ -1263,13 +1263,9 @@ __wt_page_swap_func(WT_SESSION_IMPL *session, WT_REF *held, #endif ); - /* An expected failure: WT_NOTFOUND when doing a cache-only read. */ - if (LF_ISSET(WT_READ_CACHE) && ret == WT_NOTFOUND) - return (WT_NOTFOUND); - - /* An expected failure: WT_RESTART */ - if (ret == WT_RESTART) - return (WT_RESTART); + /* Expected failures: page not found or restart. */ + if (ret == WT_NOTFOUND || ret == WT_RESTART) + return (ret); /* Discard the original held page. */ acquired = ret == 0; diff --git a/src/include/extern.h b/src/include/extern.h index 51d046f1c1f..7d8ee673e0d 100644 --- a/src/include/extern.h +++ b/src/include/extern.h @@ -116,7 +116,7 @@ extern int __wt_debug_tree( WT_SESSION_IMPL *session, WT_BTREE *btree, WT_PAGE * extern int __wt_debug_page(WT_SESSION_IMPL *session, WT_PAGE *page, const char *ofile); extern int __wt_delete_page(WT_SESSION_IMPL *session, WT_REF *ref, bool *skipp); extern void __wt_delete_page_rollback(WT_SESSION_IMPL *session, WT_REF *ref); -extern bool __wt_delete_page_skip(WT_SESSION_IMPL *session, WT_REF *ref); +extern bool __wt_delete_page_skip(WT_SESSION_IMPL *session, WT_REF *ref, bool visible_all); extern int __wt_delete_page_instantiate(WT_SESSION_IMPL *session, WT_REF *ref); extern void __wt_ref_out(WT_SESSION_IMPL *session, WT_REF *ref); extern void __wt_page_out(WT_SESSION_IMPL *session, WT_PAGE **pagep); @@ -155,6 +155,7 @@ extern void __wt_split_stash_discard(WT_SESSION_IMPL *session); extern void __wt_split_stash_discard_all( WT_SESSION_IMPL *session_safe, WT_SESSION_IMPL *session); extern int __wt_multi_to_ref(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi, WT_REF **refp, size_t *incrp); extern int __wt_split_insert(WT_SESSION_IMPL *session, WT_REF *ref); +extern int __wt_split_reverse(WT_SESSION_IMPL *session, WT_REF *ref); extern int __wt_split_rewrite(WT_SESSION_IMPL *session, WT_REF *ref); extern int __wt_split_multi(WT_SESSION_IMPL *session, WT_REF *ref, int closing); extern int __wt_btree_stat_init(WT_SESSION_IMPL *session, WT_CURSOR_STAT *cst); diff --git a/src/include/flags.h b/src/include/flags.h index e9498801bf3..99b6f1c483f 100644 --- a/src/include/flags.h +++ b/src/include/flags.h @@ -38,13 +38,14 @@ #define WT_LOG_FSYNC 0x00000008 #define WT_READ_CACHE 0x00000001 #define WT_READ_COMPACT 0x00000002 -#define WT_READ_NO_EVICT 0x00000004 -#define WT_READ_NO_GEN 0x00000008 -#define WT_READ_NO_WAIT 0x00000010 -#define WT_READ_PREV 0x00000020 -#define WT_READ_SKIP_INTL 0x00000040 -#define WT_READ_TRUNCATE 0x00000080 -#define WT_READ_WONT_NEED 0x00000100 +#define WT_READ_NO_EMPTY 0x00000004 +#define WT_READ_NO_EVICT 0x00000008 +#define WT_READ_NO_GEN 0x00000010 +#define WT_READ_NO_WAIT 0x00000020 +#define WT_READ_PREV 0x00000040 +#define WT_READ_SKIP_INTL 0x00000080 +#define WT_READ_TRUNCATE 0x00000100 +#define WT_READ_WONT_NEED 0x00000200 #define WT_SESSION_CAN_WAIT 0x00000001 #define WT_SESSION_CLEAR_EVICT_WALK 0x00000002 #define WT_SESSION_INTERNAL 0x00000004 |