Remove testing data

1 files changed, 0 insertions, 1985 deletions

diff --git a/examples/redis-unstable/src/defrag.c b/examples/redis-unstable/src/defrag.c
deleted file mode 100644
index f0bff15..0000000
--- a/examples/redis-unstable/src/defrag.c
+++ /dev/null
@@ -1,1985 +0,0 @@
-/* 
- * Active memory defragmentation
- * Try to find key / value allocations that need to be re-allocated in order 
- * to reduce external fragmentation.
- * We do that by scanning the keyspace and for each pointer we have, we can try to
- * ask the allocator if moving it to a new address will help reduce fragmentation.
- *
- * Copyright (c) 2020-Present, Redis Ltd.
- * All rights reserved.
- *
- * Copyright (c) 2024-present, Valkey contributors.
- * All rights reserved.
- *
- * Licensed under your choice of (a) the Redis Source Available License 2.0
- * (RSALv2); or (b) the Server Side Public License v1 (SSPLv1); or (c) the
- * GNU Affero General Public License v3 (AGPLv3).
- *
- * Portions of this file are available under BSD3 terms; see REDISCONTRIBUTIONS for more information.
- */
-
-#include "server.h"
-#include <stddef.h>
-#include <math.h>
-
-#ifdef HAVE_DEFRAG
-
-#define DEFRAG_CYCLE_US 500 /* Standard duration of defrag cycle (in microseconds) */
-
-typedef enum { DEFRAG_NOT_DONE = 0,
-               DEFRAG_DONE = 1 } doneStatus;
-
-/*
- * Defragmentation is performed in stages. Each stage is serviced by a stage function
- * (defragStageFn). The stage function is passed a context (void*) to defrag. The contents of that
- * context are unique to the particular stage - and may even be NULL for some stage functions. The
- * same stage function can be used multiple times (for different stages) each having a different
- * context.
- *
- * Parameters:
- *  endtime     - This is the monotonic time that the function should end and return. This ensures
- *                a bounded latency due to defrag.
- *  ctx         - A pointer to context which is unique to the stage function.
- *
- * Returns:
- *  - DEFRAG_DONE if the stage is complete
- *  - DEFRAG_NOT_DONE if there is more work to do
- */
-typedef doneStatus (*defragStageFn)(void *ctx, monotime endtime);
-
-/* Function pointer type for freeing context in defragmentation stages. */
-typedef void (*defragStageContextFreeFn)(void *ctx);
-typedef struct {
-    defragStageFn stage_fn; /* The function to be invoked for the stage */
-    defragStageContextFreeFn ctx_free_fn; /* Function to free the context */
-    void *ctx; /* Context, unique to the stage function */
-} StageDescriptor;
-
-/* Globals needed for the main defrag processing logic.
- * Doesn't include variables specific to a stage or type of data. */
-struct DefragContext {
-    monotime start_cycle;           /* Time of beginning of defrag cycle */
-    long long start_defrag_hits;    /* server.stat_active_defrag_hits captured at beginning of cycle */
-    long long start_defrag_misses;  /* server.stat_active_defrag_misses captured at beginning of cycle */
-    float start_frag_pct;           /* Fragmention percent of beginning of defrag cycle */
-    float decay_rate;               /* Defrag speed decay rate */
-
-    list *remaining_stages;         /* List of stages which remain to be processed */
-    listNode *current_stage;        /* The list node of stage that's currently being processed */
-
-    long long timeproc_id;      /* Eventloop ID of the timerproc (or AE_DELETED_EVENT_ID) */
-    monotime timeproc_end_time; /* Ending time of previous timerproc execution */
-    long timeproc_overage_us;   /* A correction value if over target CPU percent */
-};
-static struct DefragContext defrag = {0, 0, 0, 0, 1.0f};
-
-#define ITER_SLOT_DEFRAG_LUT (-2)
-#define ITER_SLOT_UNASSIGNED (-1)
-
-/* There are a number of stages which process a kvstore. To simplify this, a stage helper function
- * `defragStageKvstoreHelper()` is defined. This function aids in iterating over the kvstore. It
- * uses these definitions.
- */
-/* State of the kvstore helper. The context passed to the kvstore helper MUST BEGIN
- * with a kvstoreIterState (or be passed as NULL). */
-typedef struct {
-    kvstore *kvs;
-    int slot;   /* Consider defines ITER_SLOT_XXX for special values. */
-    unsigned long cursor;
-} kvstoreIterState;
-#define INIT_KVSTORE_STATE(kvs) ((kvstoreIterState){(kvs), ITER_SLOT_DEFRAG_LUT, 0})
-
-/* The kvstore helper uses this function to perform tasks before continuing the iteration. For the
- * main dictionary, large items are set aside and processed by this function before continuing with
- * iteration over the kvstore.
- *  endtime     - This is the monotonic time that the function should end and return.
- *  ctx         - Context for functions invoked by the helper. If provided in the call to
- *                `defragStageKvstoreHelper()`, the `kvstoreIterState` portion (at the beginning)
- *                will be updated with the current kvstore iteration status.
- *
- * Returns:
- *  - DEFRAG_DONE if the pre-continue work is complete
- *  - DEFRAG_NOT_DONE if there is more work to do
- */
-typedef doneStatus (*kvstoreHelperPreContinueFn)(void *ctx, monotime endtime);
-
-typedef struct {
-    kvstoreIterState kvstate;
-    int dbid;
-
-    /* When scanning a main kvstore, large elements are queued for later handling rather than
-     * causing a large latency spike while processing a hash table bucket. This list is only used
-     * for stage: "defragStageDbKeys". It will only contain values for the current kvstore being
-     * defragged.
-     * Note that this is a list of key names. It's possible that the key may be deleted or modified
-     * before "later" and we will search by key name to find the entry when we defrag the item later. */
-    list *defrag_later;
-    unsigned long defrag_later_cursor;
-} defragKeysCtx;
-static_assert(offsetof(defragKeysCtx, kvstate) == 0, "defragStageKvstoreHelper requires this");
-
-/* Context for subexpires */
-typedef struct {
-    estore *subexpires;
-    int slot; /* Consider defines ITER_SLOT_XXX for special values. */
-    int dbid;
-    unsigned long cursor;
-} defragSubexpiresCtx;
-
-/* Context for pubsub kvstores */
-typedef dict *(*getClientChannelsFn)(client *);
-typedef struct {
-    kvstoreIterState kvstate;
-    getClientChannelsFn getPubSubChannels;
-} defragPubSubCtx;
-static_assert(offsetof(defragPubSubCtx, kvstate) == 0, "defragStageKvstoreHelper requires this");
-
-typedef struct {
-    sds module_name;
-    unsigned long cursor;
-} defragModuleCtx;
-
-/* this method was added to jemalloc in order to help us understand which
- * pointers are worthwhile moving and which aren't */
-int je_get_defrag_hint(void* ptr);
-
-#if !defined(DEBUG_DEFRAG_FORCE)
-/* Defrag helper for generic allocations without freeing old pointer.
- *
- * Note: The caller is responsible for freeing the old pointer if this function
- * returns a non-NULL value. */
-void* activeDefragAllocWithoutFree(void *ptr) {
-    size_t size;
-    void *newptr;
-    if(!je_get_defrag_hint(ptr)) {
-        server.stat_active_defrag_misses++;
-        return NULL;
-    }
-    /* move this allocation to a new allocation.
-     * make sure not to use the thread cache. so that we don't get back the same
-     * pointers we try to free */
-    size = zmalloc_usable_size(ptr);
-    newptr = zmalloc_no_tcache(size);
-    memcpy(newptr, ptr, size);
-    server.stat_active_defrag_hits++;
-    return newptr;
-}
-
-void activeDefragFree(void *ptr) {
-    zfree_no_tcache(ptr);
-}
-
-/* Defrag helper for generic allocations.
- *
- * returns NULL in case the allocation wasn't moved.
- * when it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-void* activeDefragAlloc(void *ptr) {
-    void *newptr = activeDefragAllocWithoutFree(ptr);
-    if (newptr)
-        activeDefragFree(ptr);
-    return newptr;
-}
-
-/* Raw memory allocation for defrag, avoid using tcache. */
-void *activeDefragAllocRaw(size_t size) {
-    return zmalloc_no_tcache(size);
-}
-
-/* Raw memory free for defrag, avoid using tcache. */
-void activeDefragFreeRaw(void *ptr) {
-    activeDefragFree(ptr);
-    server.stat_active_defrag_hits++;
-}
-#else
-void *activeDefragAllocWithoutFree(void *ptr) {
-    size_t size;
-    void *newptr;
-    size = zmalloc_usable_size(ptr);
-    newptr = zmalloc(size);
-    memcpy(newptr, ptr, size);
-    server.stat_active_defrag_hits++;
-    return newptr;
-}
-
-void activeDefragFree(void *ptr) {
-    zfree(ptr);
-}
-
-void *activeDefragAlloc(void *ptr) {
-    void *newptr = activeDefragAllocWithoutFree(ptr);
-    if (newptr)
-        activeDefragFree(ptr);
-    return newptr;
-}
-
-void *activeDefragAllocRaw(size_t size) {
-    return zmalloc(size);
-}
-
-void activeDefragFreeRaw(void *ptr) {
-    zfree(ptr);
-    server.stat_active_defrag_hits++;
-}
-#endif
-
-/*Defrag helper for sds strings
- *
- * returns NULL in case the allocation wasn't moved.
- * when it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-sds activeDefragSds(sds sdsptr) {
-    void* ptr = sdsAllocPtr(sdsptr);
-    void* newptr = activeDefragAlloc(ptr);
-    if (newptr) {
-        size_t offset = sdsptr - (char*)ptr;
-        sdsptr = (char*)newptr + offset;
-        return sdsptr;
-    }
-    return NULL;
-}
-
-/* Defrag helper for hfield (entry) strings
- *
- * returns NULL in case the allocation wasn't moved.
- * when it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-Entry *activeDefragEntry(Entry *entry) {
-    Entry *ret = NULL;
-
-    /* First, defrag the entry allocation itself */
-    void *ptr = entryGetAllocPtr(entry);
-    void *newptr = activeDefragAlloc(ptr);
-    if (newptr) {
-        size_t offset = (char*)entry - (char*)ptr;
-        entry = (Entry *)((char*)newptr + offset);
-        ret = entry;
-    }
-
-    /* Then defrag the value if it's not embedded (using the potentially new entry) */
-    sds *valuePtr = entryGetValuePtrRef(entry);
-    if (valuePtr) {
-        sds new_value = activeDefragSds(*valuePtr);
-        if (new_value) *valuePtr = new_value;
-    }
-
-    return ret;
-}
-
-/* Defrag helper for hfield strings and update the reference in the dict.
- *
- * returns NULL in case the allocation wasn't moved.
- * when it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-void *activeDefragHfieldAndUpdateRef(void *ptr, void *privdata) {
-    dict *d = privdata;
-    dictEntryLink link;
-
-    /* Before the key is released, obtain the link to
-     * ensure we can safely access and update the key. */
-    link = dictFindLink(d, ptr, NULL);
-    serverAssert(link);
-
-    Entry *newEntry = activeDefragEntry(ptr);
-    if (newEntry)
-        dictSetKeyAtLink(d, newEntry, &link, 0);
-    return newEntry;
-}
-
-/* Defrag helper for robj and/or string objects with expected refcount.
- *
- * Like activeDefragStringOb, but it requires the caller to pass in the expected
- * reference count. In some cases, the caller needs to update a robj whose
- * reference count is not 1, in these cases, the caller must explicitly pass
- * in the reference count, otherwise defragmentation will not be performed.
- * Note that the caller is responsible for updating any other references to the robj. */
-robj *activeDefragStringObEx(robj* ob, int expected_refcount) {
-    robj *ret = NULL;
-    if (ob->refcount!=expected_refcount)
-        return NULL;
-
-    /* try to defrag robj (only if not an EMBSTR type (handled below). */
-    if (ob->type!=OBJ_STRING || ob->encoding!=OBJ_ENCODING_EMBSTR) {
-        if ((ret = activeDefragAlloc(ob))) {
-            ob = ret;
-        }
-    }
-
-    /* try to defrag string object */
-    if (ob->type == OBJ_STRING) {
-        if(ob->encoding==OBJ_ENCODING_RAW) {
-            sds newsds = activeDefragSds((sds)ob->ptr);
-            if (newsds) {
-                ob->ptr = newsds;
-            }
-        } else if (ob->encoding==OBJ_ENCODING_EMBSTR) {
-            /* The sds is embedded in the object allocation, calculate the
-             * offset and update the pointer in the new allocation. */
-            long ofs = (intptr_t)ob->ptr - (intptr_t)ob;
-            if ((ret = activeDefragAlloc(ob))) {
-                ret->ptr = (void*)((intptr_t)ret + ofs);
-            }
-        } else if (ob->encoding!=OBJ_ENCODING_INT) {
-            serverPanic("Unknown string encoding");
-        }
-    }
-    return ret;
-}
-
-/* Defrag helper for robj and/or string objects
- *
- * returns NULL in case the allocation wasn't moved.
- * when it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-robj *activeDefragStringOb(robj* ob) {
-    return activeDefragStringObEx(ob, 1);
-}
-
-/* Defrag helper for lua scripts
- *
- * returns NULL in case the allocation wasn't moved.
- * when it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-luaScript *activeDefragLuaScript(luaScript *script) {
-    luaScript *ret = NULL;
-
-    /* try to defrag script struct */
-    if ((ret = activeDefragAlloc(script))) {
-        script = ret;
-    }
-
-    /* try to defrag actual script object */
-    robj *ob = activeDefragStringOb(script->body);
-    if (ob) script->body = ob;
-
-    return ret;
-}
-
-/* Defrag helper for dict main allocations (dict struct, and hash tables).
- * Receives a pointer to the dict* and return a new dict* when the dict
- * struct itself was moved.
- * 
- * Returns NULL in case the allocation wasn't moved.
- * When it returns a non-null value, the old pointer was already released
- * and should NOT be accessed. */
-dict *dictDefragTables(dict *d) {
-    dict *ret = NULL;
-    dictEntry **newtable;
-    /* handle the dict struct */
-    if ((ret = activeDefragAlloc(d)))
-        d = ret;
-    /* handle the first hash table */
-    if (!d->ht_table[0]) return ret; /* created but unused */
-    newtable = activeDefragAlloc(d->ht_table[0]);
-    if (newtable)
-        d->ht_table[0] = newtable;
-    /* handle the second hash table */
-    if (d->ht_table[1]) {
-        newtable = activeDefragAlloc(d->ht_table[1]);
-        if (newtable)
-            d->ht_table[1] = newtable;
-    }
-    return ret;
-}
-
-/* Internal function used by activeDefragZsetNode */
-void zslUpdateNode(zskiplist *zsl, zskiplistNode *oldnode, zskiplistNode *newnode, zskiplistNode **update) {
-    int i;
-    for (i = 0; i < zsl->level; i++) {
-        if (update[i]->level[i].forward == oldnode)
-            update[i]->level[i].forward = newnode;
-    }
-    serverAssert(zsl->header!=oldnode);
-    if (newnode->level[0].forward) {
-        serverAssert(newnode->level[0].forward->backward==oldnode);
-        newnode->level[0].forward->backward = newnode;
-    } else {
-        serverAssert(zsl->tail==oldnode);
-        zsl->tail = newnode;
-    }
-}
-
-/* Defrag a single zset node, update dictEntry and skiplist struct */
-void activeDefragZsetNode(zset *zs, dictEntry *de, dictEntryLink plink) {
-    zskiplistNode *znode = dictGetKey(de);
-
-    /* Try to defrag the skiplist node first */
-    zskiplistNode *newnode = activeDefragAllocWithoutFree(znode);
-    if (!newnode) return; /* No defrag needed */
-
-    /* Node was defragged, now we need to update all skiplist pointers */
-    zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *iter;
-    int i;
-    double score = newnode->score;
-    sds ele = zslGetNodeElement(newnode);
-
-    /* Find all pointers that need to be updated */
-    iter = zs->zsl->header;
-    for (i = zs->zsl->level-1; i >= 0; i--) {
-        while (iter->level[i].forward &&
-            iter->level[i].forward != znode &&
-            zslCompareWithNode(score, ele, iter->level[i].forward) > 0)
-            iter = iter->level[i].forward;
-        update[i] = iter;
-    }
-
-    /* Verify we found the right node */
-    iter = iter->level[0].forward;
-    serverAssert(iter && iter == znode);
-
-    /* Update all skiplist pointers and dict key */
-    zslUpdateNode(zs->zsl, znode, newnode, update);
-    dictSetKeyAtLink(zs->dict, newnode, &plink, 0);
-
-    /* Free the old node now that all pointers have been updated */
-    activeDefragFree(znode);
-}
-
-#define DEFRAG_SDS_DICT_NO_VAL 0
-#define DEFRAG_SDS_DICT_VAL_IS_SDS 1
-#define DEFRAG_SDS_DICT_VAL_IS_STROB 2
-#define DEFRAG_SDS_DICT_VAL_VOID_PTR 3
-#define DEFRAG_SDS_DICT_VAL_LUA_SCRIPT 4
-
-void activeDefragSdsDictCallback(void *privdata, const dictEntry *de, dictEntryLink plink) {
-    UNUSED(plink);
-    UNUSED(privdata);
-    UNUSED(de);
-}
-
-void activeDefragLuaScriptDictCallback(void *privdata, const dictEntry *de, dictEntryLink plink) {
-    UNUSED(plink);
-    UNUSED(privdata);
-
-    /* If this luaScript is in the LRU list, unconditionally update the node's
-     * value pointer to the current dict key (regardless of reallocation). */
-    luaScript *script = dictGetVal(de);
-    if (script->node)
-        script->node->value = dictGetKey(de);
-}
-
-void activeDefragHfieldDictCallback(void *privdata, const dictEntry *de, dictEntryLink plink) {
-    dict *d = privdata;
-    Entry *newEntry = NULL, *entry = dictGetKey(de);
-
-    /* If the hfield does not have TTL, we directly defrag it.
-     * Fields with TTL are skipped here and will be defragmented later
-     * during the hash expiry ebuckets defragmentation phase. */
-    if (entryGetExpiry(entry) == EB_EXPIRE_TIME_INVALID) {
-        if ((newEntry = activeDefragEntry(entry))) {
-            /* Hash dicts use no_value=1, so we must use dictSetKeyAtLink */
-            dictSetKeyAtLink(d, newEntry, &plink, 0);
-        }
-    }
-}
-
-/* Defrag a dict with sds key and optional value (either ptr, sds or robj string) */
-void activeDefragSdsDict(dict* d, int val_type) {
-    unsigned long cursor = 0;
-    dictDefragFunctions defragfns = {
-        .defragAlloc = activeDefragAlloc,
-        .defragKey = (dictDefragAllocFunction *)activeDefragSds,
-        .defragVal = (val_type == DEFRAG_SDS_DICT_VAL_IS_SDS ? (dictDefragAllocFunction *)activeDefragSds :
-                      val_type == DEFRAG_SDS_DICT_VAL_IS_STROB ? (dictDefragAllocFunction *)activeDefragStringOb :
-                      val_type == DEFRAG_SDS_DICT_VAL_VOID_PTR ? (dictDefragAllocFunction *)activeDefragAlloc :
-                      val_type == DEFRAG_SDS_DICT_VAL_LUA_SCRIPT ? (dictDefragAllocFunction *)activeDefragLuaScript :
-                      NULL)
-    };
-    dictScanFunction *fn = (val_type == DEFRAG_SDS_DICT_VAL_LUA_SCRIPT ?
-        activeDefragLuaScriptDictCallback : activeDefragSdsDictCallback);
-    do {
-        cursor = dictScanDefrag(d, cursor, fn,
-                                &defragfns, NULL);
-    } while (cursor != 0);
-}
-
-/* Defrag a dict with hfield key (no separate value - value is part of entry). */
-void activeDefragHfieldDict(dict *d) {
-    unsigned long cursor = 0;
-    dictDefragFunctions defragfns = {
-        .defragAlloc = activeDefragAlloc, /* Only defrag dictEntry */
-        .defragKey = NULL, /* Will be defragmented in activeDefragHfieldDictCallback. */
-        .defragVal = NULL  /* No separate value - value is part of the entry (hfield). */
-    };
-    do {
-        cursor = dictScanDefrag(d, cursor, activeDefragHfieldDictCallback,
-                                &defragfns, d);
-    } while (cursor != 0);
-
-    /* Continue with defragmentation of hash fields that have with TTL.
-     * During the dictionary defragmentaion above, we skipped fields with TTL,
-     * Now we continue to defrag those fields by using the expiry buckets. */
-    if (d->type == &entryHashDictTypeWithHFE) {
-        cursor = 0;
-        ebDefragFunctions eb_defragfns = {
-            .defragAlloc = activeDefragAlloc,
-            .defragItem = activeDefragHfieldAndUpdateRef
-        };
-        ebuckets *eb = hashTypeGetDictMetaHFE(d);
-        while (ebScanDefrag(eb, &hashFieldExpireBucketsType, &cursor, &eb_defragfns, d)) {}
-    }
-}
-
-/* Defrag a list of ptr, sds or robj string values */
-void activeDefragQuickListNode(quicklist *ql, quicklistNode **node_ref) {
-    quicklistNode *newnode, *node = *node_ref;
-    unsigned char *newzl;
-    if ((newnode = activeDefragAlloc(node))) {
-        if (newnode->prev)
-            newnode->prev->next = newnode;
-        else
-            ql->head = newnode;
-        if (newnode->next)
-            newnode->next->prev = newnode;
-        else
-            ql->tail = newnode;
-        *node_ref = node = newnode;
-    }
-    if ((newzl = activeDefragAlloc(node->entry)))
-        node->entry = newzl;
-}
-
-void activeDefragQuickListNodes(quicklist *ql) {
-    quicklistNode *node = ql->head;
-    while (node) {
-        activeDefragQuickListNode(ql, &node);
-        node = node->next;
-    }
-}
-
-/* when the value has lots of elements, we want to handle it later and not as
- * part of the main dictionary scan. this is needed in order to prevent latency
- * spikes when handling large items */
-void defragLater(defragKeysCtx *ctx, kvobj *kv) {
-    if (!ctx->defrag_later) {
-        ctx->defrag_later = listCreate();
-        listSetFreeMethod(ctx->defrag_later, sdsfreegeneric);
-        ctx->defrag_later_cursor = 0;
-    }
-    sds key = sdsdup(kvobjGetKey(kv));
-    listAddNodeTail(ctx->defrag_later, key);
-}
-
-/* returns 0 if no more work needs to be been done, and 1 if time is up and more work is needed. */
-long scanLaterList(robj *ob, unsigned long *cursor, monotime endtime) {
-    quicklist *ql = ob->ptr;
-    quicklistNode *node;
-    long iterations = 0;
-    int bookmark_failed = 0;
-    serverAssert(ob->type == OBJ_LIST && ob->encoding == OBJ_ENCODING_QUICKLIST);
-
-    if (*cursor == 0) {
-        /* if cursor is 0, we start new iteration */
-        node = ql->head;
-    } else {
-        node = quicklistBookmarkFind(ql, "_AD");
-        if (!node) {
-            /* if the bookmark was deleted, it means we reached the end. */
-            *cursor = 0;
-            return 0;
-        }
-        node = node->next;
-    }
-
-    (*cursor)++;
-    while (node) {
-        activeDefragQuickListNode(ql, &node);
-        server.stat_active_defrag_scanned++;
-        if (++iterations > 128 && !bookmark_failed) {
-            if (getMonotonicUs() > endtime) {
-                if (!quicklistBookmarkCreate(&ql, "_AD", node)) {
-                    bookmark_failed = 1;
-                } else {
-                    ob->ptr = ql; /* bookmark creation may have re-allocated the quicklist */
-                    return 1;
-                }
-            }
-            iterations = 0;
-        }
-        node = node->next;
-    }
-    quicklistBookmarkDelete(ql, "_AD");
-    *cursor = 0;
-    return bookmark_failed? 1: 0;
-}
-
-typedef struct {
-    zset *zs;
-} scanLaterZsetData;
-
-void scanZsetCallback(void *privdata, const dictEntry *_de, dictEntryLink plink) {
-    dictEntry *de = (dictEntry*)_de;
-    scanLaterZsetData *data = privdata;
-    activeDefragZsetNode(data->zs, de, plink);
-    server.stat_active_defrag_scanned++;
-}
-
-void scanLaterZset(robj *ob, unsigned long *cursor) {
-    serverAssert(ob->type == OBJ_ZSET && ob->encoding == OBJ_ENCODING_SKIPLIST);
-    zset *zs = (zset*)ob->ptr;
-    dict *d = zs->dict;
-    scanLaterZsetData data = {zs};
-    dictDefragFunctions defragfns = {.defragAlloc = activeDefragAlloc};
-    *cursor = dictScanDefrag(d, *cursor, scanZsetCallback, &defragfns, &data);
-}
-
-/* Used as scan callback when all the work is done in the dictDefragFunctions. */
-void scanCallbackCountScanned(void *privdata, const dictEntry *de, dictEntryLink plink) {
-    UNUSED(plink);
-    UNUSED(privdata);
-    UNUSED(de);
-    server.stat_active_defrag_scanned++;
-}
-
-void scanLaterSet(robj *ob, unsigned long *cursor) {
-    serverAssert(ob->type == OBJ_SET && ob->encoding == OBJ_ENCODING_HT);
-    dict *d = ob->ptr;
-    dictDefragFunctions defragfns = {
-        .defragAlloc = activeDefragAlloc,
-        .defragKey = (dictDefragAllocFunction *)activeDefragSds
-    };
-    *cursor = dictScanDefrag(d, *cursor, scanCallbackCountScanned, &defragfns, NULL);
-}
-
-void scanLaterHash(robj *ob, unsigned long *cursor) {
-    serverAssert(ob->type == OBJ_HASH && ob->encoding == OBJ_ENCODING_HT);
-    dict *d = ob->ptr;
-
-    typedef enum {
-        HASH_DEFRAG_NONE = 0,
-        HASH_DEFRAG_DICT = 1,
-        HASH_DEFRAG_EBUCKETS = 2
-    } hashDefragPhase;
-    static hashDefragPhase defrag_phase = HASH_DEFRAG_NONE;
-
-    /* Start a new hash defrag. */
-    if (!*cursor || defrag_phase == HASH_DEFRAG_NONE)
-        defrag_phase = HASH_DEFRAG_DICT;
-
-    /* Defrag hash dictionary but skip TTL fields. */
-    if (defrag_phase == HASH_DEFRAG_DICT) {
-        dictDefragFunctions defragfns = {
-            .defragAlloc = activeDefragAlloc,
-            .defragKey = NULL, /* Will be defragmented in activeDefragHfieldDictCallback. */
-            .defragVal = NULL  /* value stored along with key as part of Entry */
-        };
-        *cursor = dictScanDefrag(d, *cursor, activeDefragHfieldDictCallback, &defragfns, d);
-
-        /* Move to next phase. */
-        if (!*cursor) defrag_phase = HASH_DEFRAG_EBUCKETS;
-    }
-
-    /* Defrag ebuckets and TTL fields. */
-    if (defrag_phase == HASH_DEFRAG_EBUCKETS) {
-        if (d->type == &entryHashDictTypeWithHFE) {
-            ebDefragFunctions eb_defragfns = {
-                .defragAlloc = activeDefragAlloc,
-                .defragItem = activeDefragHfieldAndUpdateRef
-            };
-            ebuckets *eb = hashTypeGetDictMetaHFE(d);
-            ebScanDefrag(eb, &hashFieldExpireBucketsType, cursor, &eb_defragfns, d);
-        } else {
-            /* Finish defragmentation if this dict doesn't have expired fields. */
-            *cursor = 0;
-        }
-        if (!*cursor) defrag_phase = HASH_DEFRAG_NONE;
-    }
-}
-
-void defragQuicklist(defragKeysCtx *ctx, kvobj *kv) {
-    quicklist *ql = kv->ptr, *newql;
-    serverAssert(kv->type == OBJ_LIST && kv->encoding == OBJ_ENCODING_QUICKLIST);
-    if ((newql = activeDefragAlloc(ql)))
-        kv->ptr = ql = newql;
-    if (ql->len > server.active_defrag_max_scan_fields)
-        defragLater(ctx, kv);
-    else
-        activeDefragQuickListNodes(ql);
-}
-
-void defragZsetSkiplist(defragKeysCtx *ctx, kvobj *ob) {
-    zset *zs = (zset*)ob->ptr;
-    zset *newzs;
-    zskiplist *newzsl;
-    dict *newdict;
-    struct zskiplistNode *newheader;
-    serverAssert(ob->type == OBJ_ZSET && ob->encoding == OBJ_ENCODING_SKIPLIST);
-    if ((newzs = activeDefragAlloc(zs)))
-        ob->ptr = zs = newzs;
-    if ((newzsl = activeDefragAlloc(zs->zsl)))
-        zs->zsl = newzsl;
-    if ((newheader = activeDefragAlloc(zs->zsl->header)))
-        zs->zsl->header = newheader;
-    if (dictSize(zs->dict) > server.active_defrag_max_scan_fields)
-        defragLater(ctx, ob);
-    else {
-        /* Use dictScanDefrag to iterate and defrag both dictEntry structures and skiplist nodes.
-         * dictScanDefrag handles defragging dictEntry/dictEntryNoValue structures via defragfns,
-         * and calls our callback with plink for each entry so we can defrag skiplist nodes. */
-        scanLaterZsetData data = {zs};
-        dictDefragFunctions defragfns = {.defragAlloc = activeDefragAlloc};
-        unsigned long cursor = 0;
-        do {
-            cursor = dictScanDefrag(zs->dict, cursor, scanZsetCallback, &defragfns, &data);
-        } while (cursor != 0);
-    }
-    /* defrag the dict struct and tables */
-    if ((newdict = dictDefragTables(zs->dict)))
-        zs->dict = newdict;
-}
-
-void defragHash(defragKeysCtx *ctx, kvobj *ob) {
-    dict *d, *newd;
-    serverAssert(ob->type == OBJ_HASH && ob->encoding == OBJ_ENCODING_HT);
-    d = ob->ptr;
-    if (dictSize(d) > server.active_defrag_max_scan_fields)
-        defragLater(ctx, ob);
-    else
-        activeDefragHfieldDict(d);
-    /* defrag the dict struct and tables */
-    if ((newd = dictDefragTables(ob->ptr)))
-        ob->ptr = newd;
-}
-
-void defragSet(defragKeysCtx *ctx, kvobj *ob) {
-    dict *d, *newd;
-    serverAssert(ob->type == OBJ_SET && ob->encoding == OBJ_ENCODING_HT);
-    d = ob->ptr;
-    if (dictSize(d) > server.active_defrag_max_scan_fields)
-        defragLater(ctx, ob);
-    else
-        activeDefragSdsDict(d, DEFRAG_SDS_DICT_NO_VAL);
-    /* defrag the dict struct and tables */
-    if ((newd = dictDefragTables(ob->ptr)))
-        ob->ptr = newd;
-}
-
-/* Defrag callback for radix tree iterator, called for each node,
- * used in order to defrag the nodes allocations. */
-int defragRaxNode(raxNode **noderef, void *privdata) {
-    UNUSED(privdata);
-    raxNode *newnode = activeDefragAlloc(*noderef);
-    if (newnode) {
-        *noderef = newnode;
-        return 1;
-    }
-    return 0;
-}
-
-/* returns 0 if no more work needs to be been done, and 1 if time is up and more work is needed. */
-int scanLaterStreamListpacks(robj *ob, unsigned long *cursor, monotime endtime) {
-    static unsigned char next[sizeof(streamID)];
-    raxIterator ri;
-    long iterations = 0;
-    serverAssert(ob->type == OBJ_STREAM && ob->encoding == OBJ_ENCODING_STREAM);
-
-    stream *s = ob->ptr;
-    raxStart(&ri,s->rax);
-    if (*cursor == 0) {
-        /* if cursor is 0, we start new iteration */
-        defragRaxNode(&s->rax->head, NULL);
-        /* assign the iterator node callback before the seek, so that the
-         * initial nodes that are processed till the first item are covered */
-        ri.node_cb = defragRaxNode;
-        raxSeek(&ri,"^",NULL,0);
-    } else {
-        /* if cursor is non-zero, we seek to the static 'next'.
-         * Since node_cb is set after seek operation, any node traversed during seek wouldn't
-         * be defragmented. To prevent this, we advance to next node before exiting previous
-         * run, ensuring it gets defragmented instead of being skipped during current seek. */
-        if (!raxSeek(&ri,">=", next, sizeof(next))) {
-            *cursor = 0;
-            raxStop(&ri);
-            return 0;
-        }
-        /* assign the iterator node callback after the seek, so that the
-         * initial nodes that are processed till now aren't covered */
-        ri.node_cb = defragRaxNode;
-    }
-
-    (*cursor)++;
-    while (raxNext(&ri)) {
-        void *newdata = activeDefragAlloc(ri.data);
-        if (newdata)
-            raxSetData(ri.node, ri.data=newdata);
-        server.stat_active_defrag_scanned++;
-        if (++iterations > 128) {
-            if (getMonotonicUs() > endtime) {
-                /* Move to next node. */
-                if (!raxNext(&ri)) {
-                    /* If we reached the end, we can stop */
-                    *cursor = 0;
-                    raxStop(&ri);
-                    return 0;
-                }
-                serverAssert(ri.key_len==sizeof(next));
-                memcpy(next,ri.key,ri.key_len);
-                raxStop(&ri);
-                return 1;
-            }
-            iterations = 0;
-        }
-    }
-    raxStop(&ri);
-    *cursor = 0;
-    return 0;
-}
-
-/* optional callback used defrag each rax element (not including the element pointer itself) */
-typedef void *(raxDefragFunction)(raxIterator *ri, void *privdata);
-
-/* defrag radix tree including:
- * 1) rax struct
- * 2) rax nodes
- * 3) rax entry data (only if defrag_data is specified)
- * 4) call a callback per element, and allow the callback to return a new pointer for the element */
-void defragRadixTree(rax **raxref, int defrag_data, raxDefragFunction *element_cb, void *element_cb_data) {
-    raxIterator ri;
-    rax* rax;
-    if ((rax = activeDefragAlloc(*raxref)))
-        *raxref = rax;
-    rax = *raxref;
-    raxStart(&ri,rax);
-    ri.node_cb = defragRaxNode;
-    defragRaxNode(&rax->head, NULL);
-    raxSeek(&ri,"^",NULL,0);
-    while (raxNext(&ri)) {
-        void *newdata = NULL;
-        if (element_cb)
-            newdata = element_cb(&ri, element_cb_data);
-        if (defrag_data && !newdata)
-            newdata = activeDefragAlloc(ri.data);
-        if (newdata)
-            raxSetData(ri.node, ri.data=newdata);
-    }
-    raxStop(&ri);
-}
-
-typedef struct {
-    streamCG *cg;
-    streamConsumer *c;
-} PendingEntryContext;
-
-void* defragStreamConsumerPendingEntry(raxIterator *ri, void *privdata) {
-    PendingEntryContext *ctx = privdata;
-    streamNACK *nack = ri->data, *newnack;
-    nack->consumer = ctx->c; /* update nack pointer to consumer */
-    nack->cgroup_ref_node->value = ctx->cg; /* Update the value of cgroups_ref node to the consumer group. */
-    newnack = activeDefragAlloc(nack);
-    if (newnack) {
-        /* Update consumer group pointer to the nack.
-         * pel_by_time doesn't need updating since delivery time is unchanged. */
-        void *prev;
-        raxInsert(ctx->cg->pel, ri->key, ri->key_len, newnack, &prev);
-        serverAssert(prev==nack);
-    }
-    return newnack;
-}
-
-typedef struct {
-    stream *s;
-    streamCG *cg;
-} StreamConsumerContext;
-
-void* defragStreamConsumer(raxIterator *ri, void *privdata) {
-    StreamConsumerContext *ctx = privdata;
-    stream *s = ctx->s;
-    streamCG *cg = ctx->cg;
-    streamConsumer *c = ri->data;
-    void *newc = activeDefragAlloc(c);
-    if (newc) {
-        c = newc;
-    }
-    sds newsds = activeDefragSds(c->name);
-    if (newsds)
-        c->name = newsds;
-    if (c->pel) {
-        /* Update pel back-pointer to new stream */
-        c->pel->alloc_size = &s->alloc_size;
-        PendingEntryContext pel_ctx = {cg, c};
-        defragRadixTree(&c->pel, 0, defragStreamConsumerPendingEntry, &pel_ctx);
-    }
-    return newc; /* returns NULL if c was not defragged */
-}
-
-void* defragStreamConsumerGroup(raxIterator *ri, void *privdata) {
-    stream *s = privdata;
-    streamCG *newcg, *cg = ri->data;
-    if ((newcg = activeDefragAlloc(cg)))
-        cg = newcg;
-    if (cg->pel) {
-        /* Update pel back-pointer to new stream */
-        cg->pel->alloc_size = &s->alloc_size;
-        defragRadixTree(&cg->pel, 0, NULL, NULL);
-    }
-    if (cg->pel_by_time) {
-        /* Update pel_by_time back-pointer to new stream */
-        cg->pel_by_time->alloc_size = &s->alloc_size;
-        defragRadixTree(&cg->pel_by_time, 0, NULL, NULL);
-    }
-    if (cg->consumers) {
-        /* Update consumers back-pointer to new stream */
-        cg->consumers->alloc_size = &s->alloc_size;
-        StreamConsumerContext consumer_ctx = {s, cg};
-        defragRadixTree(&cg->consumers, 0, defragStreamConsumer, &consumer_ctx);
-    }
-    return cg;
-}
-
-/* Defrag a single idmpProducer's dict and linked list entries. */
-static void defragIdmpProducer(idmpProducer *producer) {
-    if (producer->idmp_dict == NULL) return;
-
-    dict *newdict = dictDefragTables(producer->idmp_dict);
-    if (newdict)
-        producer->idmp_dict = newdict;
-
-    idmpEntry *prev = NULL;
-    idmpEntry *entry = producer->idmp_head;
-    while (entry != NULL) {
-        idmpEntry *next = entry->next;
-        idmpEntry *newentry = activeDefragAllocWithoutFree(entry);
-        if (newentry) {
-            dictEntry *de = dictFind(producer->idmp_dict, entry);
-            serverAssert(de);
-            dictSetKey(producer->idmp_dict, de, newentry);
-            if (prev)
-                prev->next = newentry;
-            else
-                producer->idmp_head = newentry;
-            if (producer->idmp_tail == entry)
-                producer->idmp_tail = newentry;
-            activeDefragFree(entry);
-            entry = newentry;
-        }
-        prev = entry;
-        entry = next;
-    }
-}
-
-/* Defrag all IDMP producers and their dict/linked list entries. */
-void defragStreamIdmpProducers(stream *s) {
-    if (s->idmp_producers == NULL) return;
-
-    /* Defrag the producers rax tree itself */
-    rax *newrax = activeDefragAlloc(s->idmp_producers);
-    if (newrax)
-        s->idmp_producers = newrax;
-
-    /* Defrag the rax head node */
-    defragRaxNode(&s->idmp_producers->head, NULL);
-
-    /* Iterate through all producers and defrag each one */
-    raxIterator ri;
-    raxStart(&ri, s->idmp_producers);
-    /* Set the node callback to defrag internal rax nodes */
-    ri.node_cb = defragRaxNode;
-    raxSeek(&ri, "^", NULL, 0);
-    while (raxNext(&ri)) {
-        idmpProducer *producer = ri.data;
-        idmpProducer *newproducer = activeDefragAlloc(producer);
-        if (newproducer) {
-            raxSetData(ri.node, ri.data=newproducer);
-            producer = newproducer;
-        }
-        defragIdmpProducer(producer);
-    }
-    raxStop(&ri);
-}
-
-void defragStream(defragKeysCtx *ctx, kvobj *ob) {
-    serverAssert(ob->type == OBJ_STREAM && ob->encoding == OBJ_ENCODING_STREAM);
-    stream *s = ob->ptr, *news;
-
-    /* handle the main struct */
-    if ((news = activeDefragAlloc(s)))
-        ob->ptr = s = news;
-
-    /* Update rax back-pointer to new stream */
-    s->rax->alloc_size = &s->alloc_size;
-    if (raxSize(s->rax) > server.active_defrag_max_scan_fields) {
-        rax *newrax = activeDefragAlloc(s->rax);
-        if (newrax)
-            s->rax = newrax;
-        defragLater(ctx, ob);
-    } else
-        defragRadixTree(&s->rax, 1, NULL, NULL);
-
-    if (s->cgroups) {
-        /* Update cgroups back-pointer to new stream */
-        s->cgroups->alloc_size = &s->alloc_size;
-        defragRadixTree(&s->cgroups, 0, defragStreamConsumerGroup, s);
-    }
-
-    if (s->cgroups_ref) {
-        /* Update cgroups_ref back-pointer to new stream */
-        s->cgroups_ref->alloc_size = &s->alloc_size;
-    }
-
-    if (s->idmp_producers) {
-        /* Defrag the producers and all idmpEntry structures in their linked lists */
-        defragStreamIdmpProducers(s);
-    }
-}
-
-/* Defrag a module key. This is either done immediately or scheduled
- * for later. Returns then number of pointers defragged.
- */
-void defragModule(defragKeysCtx *ctx, redisDb *db, kvobj *kv) {
-    serverAssert(kv->type == OBJ_MODULE);
-    robj keyobj;
-    initStaticStringObject(keyobj, kvobjGetKey(kv));
-    if (!moduleDefragValue(&keyobj, kv, db->id))
-        defragLater(ctx, kv);
-}
-
-/* Defrag a kvobj structure, taking into account optional preceding metadata.
- * For EMBSTR strings, also defrags the embedded string value in the same allocation.
- * For RAW strings and other types, only the kvobj wrapper is defragged here;
- * the value's internal data structures are defragged separately in defragKey().
- *
- * Returns NULL if the allocation wasn't moved.
- * When it returns a non-null value, the old pointer was already released
- * (unless without_free is set) and should NOT be accessed. */
-robj *activeDefragKvobj(kvobj* kv, int without_free) {
-    void *alloc, *newalloc;
-    kvobj *kvNew = NULL;
-    /* Use LONG_MIN as sentinel to detect if we have an EMBSTR string */
-    long offsetEmbstr = LONG_MIN;
-
-    /* Don't defrag kvobj's with multiple references (refcount > 1) */
-    if (kv->refcount != 1)
-        return NULL;
-
-    /* Calculate offset for EMBSTR strings */
-    if ((kv->type == OBJ_STRING) && (kv->encoding == OBJ_ENCODING_EMBSTR))
-        offsetEmbstr = (intptr_t)kv->ptr - (intptr_t)kv;
-
-    /* Defrag the kvobj allocation (including optional metadata prefix).
-     * For EMBSTR strings, this allocation also contains the embedded string data,
-     * so we'll need to recalculate the ptr offset after defragmentation (see below). */
-
-    alloc = kvobjGetAllocPtr(kv);
-    size_t metaBytes = (char *)kv - (char *)alloc;
-    if (without_free)
-        newalloc = activeDefragAllocWithoutFree(alloc);
-    else
-        newalloc = activeDefragAlloc(alloc);
-
-    if (!newalloc)
-        return NULL;
-
-    /* Update kv pointer to new allocation */
-    kvNew = (kvobj *)((char *)newalloc + metaBytes);
-
-    /* For EMBSTR strings, recalculate ptr to point to the embedded string data
-     * at the same offset within the new allocation */
-    if (offsetEmbstr != LONG_MIN)
-        kvNew->ptr = (void*)((intptr_t)kvNew + offsetEmbstr);
-
-    return kvNew;
-}
-
-/* for each key we scan in the main dict, this function will attempt to defrag
- * all the various pointers it has. */
-void defragKey(defragKeysCtx *ctx, dictEntry *de, dictEntryLink link) {
-    UNUSED(link);
-    dictEntryLink exlink = NULL;
-    kvobj *kvnew = NULL, *ob = dictGetKV(de);
-    size_t oldsize = 0;
-    redisDb *db = &server.db[ctx->dbid];
-    int slot = ctx->kvstate.slot;
-    unsigned char *newzl;
-
-    if (server.memory_tracking_per_slot)
-        oldsize = kvobjAllocSize(ob);
-
-    long long expire = kvobjGetExpire(ob);
-    /* We can't search in db->expires for that KV after we've released
-     * the pointer it holds, since it won't be able to do the string
-     * compare. Search it before, if needed. */ 
-     if (expire != -1) {
-         exlink = kvstoreDictFindLink(db->expires, slot, kvobjGetKey(ob), NULL);
-         serverAssert(exlink != NULL);
-     }
-
-    /* Try to defrag robj. For hash objects with HFEs,
-     * defer defragmentation until processing db's subexpires. */
-    if (!(ob->type == OBJ_HASH && hashTypeGetMinExpire(ob, 0) != EB_EXPIRE_TIME_INVALID)) {
-        /* If the dict doesn't have metadata, we directly defrag it. */
-        kvnew = activeDefragKvobj(ob, 0);
-    }
-    if (kvnew) {
-        kvstoreDictSetAtLink(db->keys, slot, kvnew, &link, 0);
-        if (expire != -1)
-            kvstoreDictSetAtLink(db->expires, slot, kvnew, &exlink, 0);
-        ob = kvnew;
-    }
-
-    if (ob->type == OBJ_STRING) {
-        /* Only defrag strings with refcount==1 (String might be shared as dict 
-         * keys, e.g. pub/sub channels, and may be accessed by IO threads. Other 
-         * types are never used as dict keys) */
-        if ((ob->refcount==1) && (ob->encoding == OBJ_ENCODING_RAW)) {
-            /* For RAW strings, defrag the separate SDS allocation */
-            sds newsds = activeDefragSds((sds)ob->ptr);
-            if (newsds) ob->ptr = newsds;
-        } 
-    } else if (ob->type == OBJ_LIST) {
-        if (ob->encoding == OBJ_ENCODING_QUICKLIST) {
-            defragQuicklist(ctx, ob);
-        } else if (ob->encoding == OBJ_ENCODING_LISTPACK) {
-            if ((newzl = activeDefragAlloc(ob->ptr)))
-                ob->ptr = newzl;
-        } else {
-            serverPanic("Unknown list encoding");
-        }
-    } else if (ob->type == OBJ_SET) {
-        if (ob->encoding == OBJ_ENCODING_HT) {
-            defragSet(ctx, ob);
-        } else if (ob->encoding == OBJ_ENCODING_INTSET ||
-                   ob->encoding == OBJ_ENCODING_LISTPACK)
-        {
-            void *newptr, *ptr = ob->ptr;
-            if ((newptr = activeDefragAlloc(ptr)))
-                ob->ptr = newptr;
-        } else {
-            serverPanic("Unknown set encoding");
-        }
-    } else if (ob->type == OBJ_ZSET) {
-        if (ob->encoding == OBJ_ENCODING_LISTPACK) {
-            if ((newzl = activeDefragAlloc(ob->ptr)))
-                ob->ptr = newzl;
-        } else if (ob->encoding == OBJ_ENCODING_SKIPLIST) {
-            defragZsetSkiplist(ctx, ob);
-        } else {
-            serverPanic("Unknown sorted set encoding");
-        }
-    } else if (ob->type == OBJ_HASH) {
-        if (ob->encoding == OBJ_ENCODING_LISTPACK) {
-            if ((newzl = activeDefragAlloc(ob->ptr)))
-                ob->ptr = newzl;
-        } else if (ob->encoding == OBJ_ENCODING_LISTPACK_EX) {
-            listpackEx *newlpt, *lpt = (listpackEx*)ob->ptr;
-            if ((newlpt = activeDefragAlloc(lpt)))
-                ob->ptr = lpt = newlpt;
-            if ((newzl = activeDefragAlloc(lpt->lp)))
-                lpt->lp = newzl;
-        } else if (ob->encoding == OBJ_ENCODING_HT) {
-            defragHash(ctx, ob);
-        } else {
-            serverPanic("Unknown hash encoding");
-        }
-    } else if (ob->type == OBJ_STREAM) {
-        defragStream(ctx, ob);
-    } else if (ob->type == OBJ_MODULE) {
-        defragModule(ctx,db, ob);
-    } else {
-        serverPanic("Unknown object type");
-    }
-    if (server.memory_tracking_per_slot)
-        updateSlotAllocSize(db, slot, oldsize, kvobjAllocSize(ob));
-}
-
-/* Defrag scan callback for the main db dictionary. */
-static void dbKeysScanCallback(void *privdata, const dictEntry *de, dictEntryLink plink) {
-    long long hits_before = server.stat_active_defrag_hits;
-    defragKey((defragKeysCtx *)privdata, (dictEntry *)de, plink);
-    if (server.stat_active_defrag_hits != hits_before)
-        server.stat_active_defrag_key_hits++;
-    else
-        server.stat_active_defrag_key_misses++;
-    server.stat_active_defrag_scanned++;
-}
-
-#if !defined(DEBUG_DEFRAG_FORCE)
-/* Utility function to get the fragmentation ratio from jemalloc.
- * It is critical to do that by comparing only heap maps that belong to
- * jemalloc, and skip ones the jemalloc keeps as spare. Since we use this
- * fragmentation ratio in order to decide if a defrag action should be taken
- * or not, a false detection can cause the defragmenter to waste a lot of CPU
- * without the possibility of getting any results. */
-float getAllocatorFragmentation(size_t *out_frag_bytes) {
-    size_t resident, active, allocated, frag_smallbins_bytes;
-    zmalloc_get_allocator_info(1, &allocated, &active, &resident, NULL, NULL, &frag_smallbins_bytes);
-
-    if (server.lua_arena != UINT_MAX) {
-        size_t lua_resident, lua_active, lua_allocated, lua_frag_smallbins_bytes;
-        zmalloc_get_allocator_info_by_arena(server.lua_arena, 0, &lua_allocated, &lua_active, &lua_resident, &lua_frag_smallbins_bytes);
-        resident -= lua_resident;
-        active -= lua_active;
-        allocated -= lua_allocated;
-        frag_smallbins_bytes -= lua_frag_smallbins_bytes;
-    }
-
-    /* Calculate the fragmentation ratio as the proportion of wasted memory in small
-     * bins (which are defraggable) relative to the total allocated memory (including large bins).
-     * This is because otherwise, if most of the memory usage is large bins, we may show high percentage,
-     * despite the fact it's not a lot of memory for the user. */
-    float frag_pct = (float)frag_smallbins_bytes / allocated * 100;
-    float rss_pct = ((float)resident / allocated)*100 - 100;
-    size_t rss_bytes = resident - allocated;
-    if(out_frag_bytes)
-        *out_frag_bytes = frag_smallbins_bytes;
-    serverLog(LL_DEBUG,
-        "allocated=%zu, active=%zu, resident=%zu, frag=%.2f%% (%.2f%% rss), frag_bytes=%zu (%zu rss)",
-        allocated, active, resident, frag_pct, rss_pct, frag_smallbins_bytes, rss_bytes);
-    return frag_pct;
-}
-#else
-float getAllocatorFragmentation(size_t *out_frag_bytes) {
-    if (out_frag_bytes)
-        *out_frag_bytes = SIZE_MAX;
-    return 99; /* The maximum percentage of fragmentation */
-}
-#endif
-
-/* Defrag scan callback for the pubsub dictionary. */
-void defragPubsubScanCallback(void *privdata, const dictEntry *de, dictEntryLink plink) {
-    UNUSED(plink);
-    defragPubSubCtx *ctx = privdata;
-    kvstore *pubsub_channels = ctx->kvstate.kvs;
-    robj *newchannel, *channel = dictGetKey(de);
-    dict *newclients, *clients = dictGetVal(de);
-
-    /* Try to defrag the channel name. */
-    serverAssert(channel->refcount == (int)dictSize(clients) + 1);
-    newchannel = activeDefragStringObEx(channel, dictSize(clients) + 1);
-    if (newchannel) {
-        kvstoreDictSetKey(pubsub_channels, ctx->kvstate.slot, (dictEntry*)de, newchannel);
-
-        /* The channel name is shared by the client's pubsub(shard) and server's
-         * pubsub(shard), after defraging the channel name, we need to update
-         * the reference in the clients' dictionary. */
-        dictIterator di;
-        dictEntry *clientde;
-        dictInitIterator(&di, clients);
-        while((clientde = dictNext(&di)) != NULL) {
-            client *c = dictGetKey(clientde);
-            dict *client_channels = ctx->getPubSubChannels(c);
-            uint64_t hash = dictGetHash(client_channels, newchannel);
-            dictEntry *pubsub_channel = dictFindByHashAndPtr(client_channels, channel, hash);
-            serverAssert(pubsub_channel);
-            dictSetKey(ctx->getPubSubChannels(c), pubsub_channel, newchannel);
-        }
-        dictResetIterator(&di);
-    }
-
-    /* Try to defrag the dictionary of clients that is stored as the value part. */
-    if ((newclients = dictDefragTables(clients)))
-        kvstoreDictSetVal(pubsub_channels, ctx->kvstate.slot, (dictEntry *)de, newclients);
-
-    server.stat_active_defrag_scanned++;
-}
-
-/* returns 0 more work may or may not be needed (see non-zero cursor),
- * and 1 if time is up and more work is needed. */
-int defragLaterItem(kvobj *ob, unsigned long *cursor, monotime endtime, int dbid) {
-    if (ob) {
-        if (ob->type == OBJ_LIST && ob->encoding == OBJ_ENCODING_QUICKLIST) {
-            return scanLaterList(ob, cursor, endtime);
-        } else if (ob->type == OBJ_SET && ob->encoding == OBJ_ENCODING_HT) {
-            scanLaterSet(ob, cursor);
-        } else if (ob->type == OBJ_ZSET && ob->encoding == OBJ_ENCODING_SKIPLIST) {
-            scanLaterZset(ob, cursor);
-        } else if (ob->type == OBJ_HASH && ob->encoding == OBJ_ENCODING_HT) {
-            scanLaterHash(ob, cursor);
-        } else if (ob->type == OBJ_STREAM && ob->encoding == OBJ_ENCODING_STREAM) {
-            return scanLaterStreamListpacks(ob, cursor, endtime);
-        } else if (ob->type == OBJ_MODULE) {
-            robj keyobj;
-            initStaticStringObject(keyobj, kvobjGetKey(ob));
-            return moduleLateDefrag(&keyobj, ob, cursor, endtime, dbid);
-        } else {
-            *cursor = 0; /* object type/encoding may have changed since we schedule it for later */
-        }
-    } else {
-        *cursor = 0; /* object may have been deleted already */
-    }
-    return 0;
-}
-
-static int defragIsRunning(void) {
-    return (defrag.timeproc_id > 0);
-}
-
-/* A kvstoreHelperPreContinueFn */
-static doneStatus defragLaterStep(void *ctx, monotime endtime) {
-    defragKeysCtx *defrag_keys_ctx = ctx;
-    redisDb *db = &server.db[defrag_keys_ctx->dbid];
-    int slot = defrag_keys_ctx->kvstate.slot;
-    size_t oldsize = 0;
-
-    unsigned int iterations = 0;
-    unsigned long long prev_defragged = server.stat_active_defrag_hits;
-    unsigned long long prev_scanned = server.stat_active_defrag_scanned;
-
-    while (defrag_keys_ctx->defrag_later && listLength(defrag_keys_ctx->defrag_later) > 0) {
-        listNode *head = listFirst(defrag_keys_ctx->defrag_later);
-        sds key = head->value;
-        dictEntry *de = kvstoreDictFind(defrag_keys_ctx->kvstate.kvs, defrag_keys_ctx->kvstate.slot, key);
-        kvobj *kv = de ? dictGetKV(de) : NULL;
-
-        long long key_defragged = server.stat_active_defrag_hits;
-        if (server.memory_tracking_per_slot && kv)
-            oldsize = kvobjAllocSize(kv);
-        int timeout = (defragLaterItem(kv, &defrag_keys_ctx->defrag_later_cursor, endtime, defrag_keys_ctx->dbid) == 1);
-        if (server.memory_tracking_per_slot && kv)
-            updateSlotAllocSize(db, slot, oldsize, kvobjAllocSize(kv));
-        if (key_defragged != server.stat_active_defrag_hits) {
-            server.stat_active_defrag_key_hits++;
-        } else {
-            server.stat_active_defrag_key_misses++;
-        }
-
-        if (timeout) break;
-
-        if (defrag_keys_ctx->defrag_later_cursor == 0) {
-            /* the item is finished, move on */
-            listDelNode(defrag_keys_ctx->defrag_later, head);
-        }
-
-        if (++iterations > 16 || server.stat_active_defrag_hits - prev_defragged > 512 ||
-            server.stat_active_defrag_scanned - prev_scanned > 64) {
-            if (getMonotonicUs() > endtime) break;
-            iterations = 0;
-            prev_defragged = server.stat_active_defrag_hits;
-            prev_scanned = server.stat_active_defrag_scanned;
-        }
-    }
-
-    return (!defrag_keys_ctx->defrag_later || listLength(defrag_keys_ctx->defrag_later) == 0) ? DEFRAG_DONE : DEFRAG_NOT_DONE;
-}
-
-#define INTERPOLATE(x, x1, x2, y1, y2) ( (y1) + ((x)-(x1)) * ((y2)-(y1)) / ((x2)-(x1)) )
-#define LIMIT(y, min, max) ((y)<(min)? min: ((y)>(max)? max: (y)))
-
-/* decide if defrag is needed, and at what CPU effort to invest in it */
-void computeDefragCycles(void) {
-    size_t frag_bytes;
-    float frag_pct = getAllocatorFragmentation(&frag_bytes);
-    /* If we're not already running, and below the threshold, exit. */
-    if (!server.active_defrag_running) {
-        if(frag_pct < server.active_defrag_threshold_lower || frag_bytes < server.active_defrag_ignore_bytes)
-            return;
-    }
-
-    /* Calculate the adaptive aggressiveness of the defrag based on the current
-     * fragmentation and configurations. */
-    int cpu_pct = INTERPOLATE(frag_pct,
-            server.active_defrag_threshold_lower,
-            server.active_defrag_threshold_upper,
-            server.active_defrag_cycle_min,
-            server.active_defrag_cycle_max);
-    cpu_pct *= defrag.decay_rate;
-    cpu_pct = LIMIT(cpu_pct,
-            server.active_defrag_cycle_min,
-            server.active_defrag_cycle_max);
-
-    /* Normally we allow increasing the aggressiveness during a scan, but don't
-     * reduce it, since we should not lower the aggressiveness when fragmentation
-     * drops. But when a configuration is made, we should reconsider it. */
-    if (cpu_pct > server.active_defrag_running ||
-        server.active_defrag_configuration_changed)
-    {
-        server.active_defrag_configuration_changed = 0;
-        if (defragIsRunning()) {
-            serverLog(LL_VERBOSE, "Changing active defrag CPU, frag=%.0f%%, frag_bytes=%zu, cpu=%d%%",
-                      frag_pct, frag_bytes, cpu_pct);
-        } else {
-            serverLog(LL_VERBOSE,
-                "Starting active defrag, frag=%.0f%%, frag_bytes=%zu, cpu=%d%%",
-                frag_pct, frag_bytes, cpu_pct);
-        }
-        server.active_defrag_running = cpu_pct;
-    }
-}
-
-/* This helper function handles most of the work for iterating over a kvstore. 'privdata', if
- * provided, MUST begin with 'kvstoreIterState' and this part is automatically updated by this
- * function during the iteration. */
-static doneStatus defragStageKvstoreHelper(monotime endtime,
-                                           void *ctx,
-                                           dictScanFunction scan_fn,
-                                           kvstoreHelperPreContinueFn precontinue_fn,
-                                           dictDefragFunctions *defragfns)
-{
-    unsigned int iterations = 0;
-    unsigned long long prev_defragged = server.stat_active_defrag_hits;
-    unsigned long long prev_scanned = server.stat_active_defrag_scanned;
-    kvstoreIterState *state = (kvstoreIterState*)ctx;
-
-    if (state->slot == ITER_SLOT_DEFRAG_LUT) {
-        /* Before we start scanning the kvstore, handle the main structures */
-        do {
-            state->cursor = kvstoreDictLUTDefrag(state->kvs, state->cursor, dictDefragTables);
-            if (getMonotonicUs() >= endtime) return DEFRAG_NOT_DONE;
-        } while (state->cursor != 0);
-        state->slot = ITER_SLOT_UNASSIGNED;
-    }
-
-    while (1) {
-        if (++iterations > 16 || server.stat_active_defrag_hits - prev_defragged > 512 || server.stat_active_defrag_scanned - prev_scanned > 64) {
-            if (getMonotonicUs() >= endtime) break;
-            iterations = 0;
-            prev_defragged = server.stat_active_defrag_hits;
-            prev_scanned = server.stat_active_defrag_scanned;
-        }
-
-        if (precontinue_fn) {
-            if (precontinue_fn(ctx, endtime) == DEFRAG_NOT_DONE) return DEFRAG_NOT_DONE;
-        }
-
-        if (!state->cursor) {
-            /* If there's no cursor, we're ready to begin a new kvstore slot. */
-            if (state->slot == ITER_SLOT_UNASSIGNED) {
-                state->slot = kvstoreGetFirstNonEmptyDictIndex(state->kvs);
-            } else {
-                state->slot = kvstoreGetNextNonEmptyDictIndex(state->kvs, state->slot);
-            }
-
-            if (state->slot == ITER_SLOT_UNASSIGNED) return DEFRAG_DONE;
-        }
-
-        /* Whatever privdata's actual type, this function requires that it begins with kvstoreIterState. */
-        state->cursor = kvstoreDictScanDefrag(state->kvs, state->slot, state->cursor,
-                                             scan_fn, defragfns, ctx);
-    }
-
-    return DEFRAG_NOT_DONE;
-}
-
-static doneStatus defragStageDbKeys(void *ctx, monotime endtime) {
-    defragKeysCtx *defrag_keys_ctx = ctx;
-    redisDb *db = &server.db[defrag_keys_ctx->dbid];
-    if (db->keys != defrag_keys_ctx->kvstate.kvs) {
-        /* There has been a change of the kvs (flushdb, swapdb, etc.). Just complete the stage. */
-        return DEFRAG_DONE;
-    }
-
-    /* Note: for DB keys, we use the start/finish callback to fix an expires table entry if
-     * the main DB entry has been moved. */
-    static dictDefragFunctions defragfns = {
-        .defragAlloc = activeDefragAlloc,
-        .defragKey = NULL, /* Handled by dbKeysScanCallback */
-        .defragVal = NULL, /* Handled by dbKeysScanCallback */
-    };
-
-    return defragStageKvstoreHelper(endtime, ctx,
-        dbKeysScanCallback, defragLaterStep, &defragfns);
-}
-
-static doneStatus defragStageExpiresKvstore(void *ctx, monotime endtime) {
-    defragKeysCtx *defrag_keys_ctx = ctx;
-    redisDb *db = &server.db[defrag_keys_ctx->dbid];
-    if (db->expires != defrag_keys_ctx->kvstate.kvs) {
-        /* There has been a change of the kvs (flushdb, swapdb, etc.). Just complete the stage. */
-        return DEFRAG_DONE;
-    }
-
-    static dictDefragFunctions defragfns = {
-        .defragAlloc = activeDefragAlloc,
-        .defragKey = NULL, /* Not needed for expires (just a ref) */
-        .defragVal = NULL, /* Not needed for expires (no value) */
-    };
-    return defragStageKvstoreHelper(endtime, ctx,
-        scanCallbackCountScanned, NULL, &defragfns);
-}
-
-/* Defrag (hash) object with subexpiry and update its reference in the DB keys. */
-void *activeDefragSubexpiresOB(void *ptr, void *privdata) {
-    redisDb *db = privdata;
-    dictEntryLink link, exlink = NULL;
-    kvobj *newkv, *kv = ptr;
-    sds keystr = kvobjGetKey(kv);
-    unsigned int slot = calculateKeySlot(keystr);
-
-    serverAssert(kv->type == OBJ_HASH); /* Currently relevant only for hashes */
-
-    long long expire = kvobjGetExpire(kv);
-    /* We can't search in db->expires for that KV after we've released
-     * the pointer it holds, since it won't be able to do the string
-     * compare. Search it before, if needed. */
-    if (expire != -1) {
-        exlink = kvstoreDictFindLink(db->expires, slot, keystr, NULL);
-        serverAssert(exlink != NULL);
-    }
-
-    if ((newkv = activeDefragKvobj(kv, 1))) {
-        /* Update its reference in the DB keys. */
-        link = kvstoreDictFindLink(db->keys, slot, keystr, NULL);
-        serverAssert(link != NULL);
-        kvstoreDictSetAtLink(db->keys, slot, newkv, &link, 0);
-        if (expire != -1)
-            kvstoreDictSetAtLink(db->expires, slot, newkv, &exlink, 0);
-        activeDefragFree(kvobjGetAllocPtr(kv));
-    }
-    return newkv;
-}
-
-static doneStatus defragStageSubexpires(void *ctx, monotime endtime) {
-    unsigned int iterations = 0;
-    unsigned long long prev_defragged = server.stat_active_defrag_hits;
-    unsigned long long prev_scanned = server.stat_active_defrag_scanned;
-    defragSubexpiresCtx *subctx = ctx;
-    redisDb *db = &server.db[subctx->dbid];
-    estore *subexpires = db->subexpires;
-
-    /* If estore changed (flushdb, swapdb, etc.), Just complete the stage. */
-    if (db->subexpires != subctx->subexpires) {
-        return DEFRAG_DONE;
-    }
-
-    ebDefragFunctions eb_defragfns = {
-        .defragAlloc = activeDefragAlloc,
-        .defragItem = activeDefragSubexpiresOB
-    };
-
-    while (1) {
-        if (++iterations > 16 ||
-            server.stat_active_defrag_hits - prev_defragged > 512 ||
-            server.stat_active_defrag_scanned - prev_scanned > 64)
-        {
-            if (getMonotonicUs() >= endtime) break;
-            iterations = 0;
-            prev_defragged = server.stat_active_defrag_hits;
-            prev_scanned = server.stat_active_defrag_scanned;
-        }
-
-        /* If there's no cursor, we're ready to begin a new estore slot. */
-        if (!subctx->cursor) {
-            if (subctx->slot == ITER_SLOT_UNASSIGNED) {
-                subctx->slot = estoreGetFirstNonEmptyBucket(subexpires);
-            } else {
-                subctx->slot = estoreGetNextNonEmptyBucket(subexpires, subctx->slot);
-            }
-
-            if (subctx->slot == ITER_SLOT_UNASSIGNED) return DEFRAG_DONE;
-        }
-
-        /* Get the ebuckets for the current slot and scan it */
-        ebuckets *bucket = estoreGetBuckets(subexpires, subctx->slot);
-        if (!ebScanDefrag(bucket, &subexpiresBucketsType, &subctx->cursor, &eb_defragfns, db))
-            subctx->cursor = 0; /* Reset cursor to move to next slot */
-    }
-
-    return DEFRAG_NOT_DONE;
-}
-
-static doneStatus defragStagePubsubKvstore(void *ctx, monotime endtime) {
-    static dictDefragFunctions defragfns = {
-        .defragAlloc = activeDefragAlloc,
-        .defragKey = NULL, /* Handled by defragPubsubScanCallback */
-        .defragVal = NULL, /* Not needed for expires (no value) */
-    };
-
-    return defragStageKvstoreHelper(endtime, ctx,
-        defragPubsubScanCallback, NULL, &defragfns);
-}
-
-static doneStatus defragLuaScripts(void *ctx, monotime endtime) {
-    UNUSED(endtime);
-    UNUSED(ctx);
-    activeDefragSdsDict(evalScriptsDict(), DEFRAG_SDS_DICT_VAL_LUA_SCRIPT);
-    return DEFRAG_DONE;
-}
-
-/* Handles defragmentation of module global data. This is a stage function
- * that gets called periodically during the active defragmentation process. */
-static doneStatus defragModuleGlobals(void *ctx, monotime endtime) {
-    defragModuleCtx *defrag_module_ctx = ctx;
-
-    RedisModule *module = moduleGetHandleByName(defrag_module_ctx->module_name);
-    if (!module) {
-        /* Module has been unloaded, nothing to defrag. */
-        return DEFRAG_DONE;
-    }
-    /* Interval shouldn't exceed 1 hour  */
-    serverAssert(!endtime || llabs((long long)endtime - (long long)getMonotonicUs()) < 60*60*1000*1000LL);
-
-    /* Call appropriate version of module's defrag callback:
-     * 1. Version 2 (defrag_cb_2): Supports incremental defrag and returns whether more work is needed
-     * 2. Version 1 (defrag_cb): Legacy version, performs all work in one call.
-     *    Note: V1 doesn't support incremental defragmentation, may block for longer periods. */
-    RedisModuleDefragCtx defrag_ctx = { endtime, &defrag_module_ctx->cursor, NULL, -1, -1, -1 };
-    if (module->defrag_cb_2) {
-        return module->defrag_cb_2(&defrag_ctx) ? DEFRAG_NOT_DONE : DEFRAG_DONE;
-    } else if (module->defrag_cb) {
-        module->defrag_cb(&defrag_ctx);
-        return DEFRAG_DONE;
-    } else {
-        redis_unreachable();
-    }
-}
-
-static void freeDefragKeysContext(void *ctx) {
-    defragKeysCtx *defrag_keys_ctx = ctx;
-    if (defrag_keys_ctx->defrag_later) {
-        listRelease(defrag_keys_ctx->defrag_later);
-    }
-    zfree(defrag_keys_ctx);
-}
-
-static void freeDefragModelContext(void *ctx) {
-    defragModuleCtx *defrag_model_ctx = ctx;
-    sdsfree(defrag_model_ctx->module_name);
-    zfree(defrag_model_ctx);
-}
-
-static void freeDefragContext(void *ptr) {
-    StageDescriptor *stage = ptr;
-    if (stage->ctx_free_fn)
-        stage->ctx_free_fn(stage->ctx);
-    zfree(stage);
-}
-
-static void addDefragStage(defragStageFn stage_fn, defragStageContextFreeFn ctx_free_fn, void *ctx) {
-    StageDescriptor *stage = zmalloc(sizeof(StageDescriptor));
-    stage->stage_fn = stage_fn;
-    stage->ctx_free_fn = ctx_free_fn;
-    stage->ctx = ctx;
-    listAddNodeTail(defrag.remaining_stages, stage);
-}
-
-/* Updates the defrag decay rate based on the observed effectiveness of the defrag process.
- * The decay rate is used to gradually slow down defrag when it's not being effective. */
-static void updateDefragDecayRate(float frag_pct) {
-    long long last_hits = server.stat_active_defrag_hits - defrag.start_defrag_hits;
-    long long last_misses = server.stat_active_defrag_misses - defrag.start_defrag_misses;
-    float last_frag_pct_change = defrag.start_frag_pct - frag_pct;
-    /* When defragmentation efficiency is low, we gradually reduce the
-     * speed for the next cycle to avoid CPU waste. However, in the
-     * following two cases, we keep the normal speed:
-     * 1) If the fragmentation percentage has increased or decreased by more than 2%.
-     * 2) If the fragmentation percentage decrease is small, but hits are above 1%,
-     *    we still keep the normal speed. */
-    if (fabs(last_frag_pct_change) > 2 ||
-        (last_frag_pct_change < 0 && last_hits >= (last_hits + last_misses) * 0.01))
-    {
-        defrag.decay_rate = 1.0f;
-    } else {
-        defrag.decay_rate *= 0.9;
-    }
-}
-
-/* Called at the end of a complete defrag cycle, or when defrag is terminated */
-static void endDefragCycle(int normal_termination) {
-    if (normal_termination) {
-        /* For normal termination, we expect... */
-        serverAssert(!defrag.current_stage);
-        serverAssert(listLength(defrag.remaining_stages) == 0);
-    } else {
-        /* Defrag is being terminated abnormally */
-        aeDeleteTimeEvent(server.el, defrag.timeproc_id);
-
-        if (defrag.current_stage) {
-            listDelNode(defrag.remaining_stages, defrag.current_stage);
-            defrag.current_stage = NULL;
-        }
-    }
-    defrag.timeproc_id = AE_DELETED_EVENT_ID;
-
-    listRelease(defrag.remaining_stages);
-    defrag.remaining_stages = NULL;
-
-    size_t frag_bytes;
-    float frag_pct = getAllocatorFragmentation(&frag_bytes);
-    serverLog(LL_VERBOSE, "Active defrag done in %dms, reallocated=%d, frag=%.0f%%, frag_bytes=%zu",
-              (int)elapsedMs(defrag.start_cycle), (int)(server.stat_active_defrag_hits - defrag.start_defrag_hits),
-              frag_pct, frag_bytes);
-
-    server.stat_total_active_defrag_time += elapsedUs(server.stat_last_active_defrag_time);
-    server.stat_last_active_defrag_time = 0;
-    server.active_defrag_running = 0;
-
-    updateDefragDecayRate(frag_pct);
-    moduleDefragEnd();
-
-    /* Immediately check to see if we should start another defrag cycle. */
-    activeDefragCycle();
-}
-
-/* Must be called at the start of the timeProc as it measures the delay from the end of the previous
- * timeProc invocation when performing the computation. */
-static int computeDefragCycleUs(void) {
-    long dutyCycleUs;
-
-    int targetCpuPercent = server.active_defrag_running;
-    serverAssert(targetCpuPercent > 0 && targetCpuPercent < 100);
-
-    static int prevCpuPercent = 0; /* STATIC - this persists */
-    if (targetCpuPercent != prevCpuPercent) {
-        /* If the targetCpuPercent changes, the value might be different from when the last wait
-         * time was computed. In this case, don't consider wait time. (This is really only an
-         * issue in crazy tests that dramatically increase CPU while defrag is running.) */
-        defrag.timeproc_end_time = 0;
-        prevCpuPercent = targetCpuPercent;
-    }
-
-    /* Given when the last duty cycle ended, compute time needed to achieve the desired percentage. */
-    if (defrag.timeproc_end_time == 0) {
-        /* Either the first call to the timeProc, or we were paused for some reason. */
-        defrag.timeproc_overage_us = 0;
-        dutyCycleUs = DEFRAG_CYCLE_US;
-    } else {
-        long waitedUs = getMonotonicUs() - defrag.timeproc_end_time;
-        /* Given the elapsed wait time between calls, compute the necessary duty time needed to
-         * achieve the desired CPU percentage.
-         * With:  D = duty time, W = wait time, P = percent
-         * Solve:    D          P
-         *         -----   =  -----
-         *         D + W       100
-         * Solving for D:
-         *     D = P * W / (100 - P)
-         *
-         * Note that dutyCycleUs addresses starvation. If the wait time was long, we will compensate
-         * with a proportionately long duty-cycle. This won't significantly affect perceived
-         * latency, because clients are already being impacted by the long cycle time which caused
-         * the starvation of the timer. */
-        dutyCycleUs = targetCpuPercent * waitedUs / (100 - targetCpuPercent);
-
-        /* Also adjust for any accumulated overage. */
-        dutyCycleUs -= defrag.timeproc_overage_us;
-        defrag.timeproc_overage_us = 0;
-
-        if (dutyCycleUs < DEFRAG_CYCLE_US) {
-            /* We never reduce our cycle time, that would increase overhead. Instead, we track this
-             * as part of the overage, and increase wait time between cycles. */
-            defrag.timeproc_overage_us = DEFRAG_CYCLE_US - dutyCycleUs;
-            dutyCycleUs = DEFRAG_CYCLE_US;
-        } else if (dutyCycleUs > DEFRAG_CYCLE_US * 10) {
-            /* Add a time limit for the defrag duty cycle to prevent excessive latency.
-             * When latency is already high (indicated by a long time between calls),
-             * we don't want to make it worse by running defrag for too long. */
-            dutyCycleUs = DEFRAG_CYCLE_US * 10;
-        }
-    }
-    return dutyCycleUs;
-}
-
-/* Must be called at the end of the timeProc as it records the timeproc_end_time for use in the next
- * computeDefragCycleUs computation. */
-static int computeDelayMs(monotime intendedEndtime) {
-    defrag.timeproc_end_time = getMonotonicUs();
-    long overage = defrag.timeproc_end_time - intendedEndtime;
-    defrag.timeproc_overage_us += overage; /* track over/under desired CPU */
-    /* Allow negative overage (underage) to count against existing overage, but don't allow
-     * underage (from short stages) to be accumulated. */
-    if (defrag.timeproc_overage_us < 0) defrag.timeproc_overage_us = 0;
-
-    int targetCpuPercent = server.active_defrag_running;
-    serverAssert(targetCpuPercent > 0 && targetCpuPercent < 100);
-
-    /* Given the desired duty cycle, what inter-cycle delay do we need to achieve that? */
-    /* We want to achieve a specific CPU percent. To do that, we can't use a skewed computation. */
-    /* Example, if we run for 1ms and delay 10ms, that's NOT 10%, because the total cycle time is 11ms. */
-    /* Instead, if we rum for 1ms, our total time should be 10ms. So the delay is only 9ms. */
-    long totalCycleTimeUs = DEFRAG_CYCLE_US * 100 / targetCpuPercent;
-    long delayUs = totalCycleTimeUs - DEFRAG_CYCLE_US;
-    /* Only increase delay by the fraction of the overage that would be non-duty-cycle */
-    delayUs += defrag.timeproc_overage_us * (100 - targetCpuPercent) / 100;
-    if (delayUs < 0) delayUs = 0;
-    long delayMs = delayUs / 1000; /* round down */
-    return delayMs;
-}
-
-/* An independent time proc for defrag. While defrag is running, this is called much more often
- * than the server cron. Frequent short calls provides low latency impact. */
-static int activeDefragTimeProc(struct aeEventLoop *eventLoop, long long id, void *clientData) {
-    UNUSED(eventLoop);
-    UNUSED(id);
-    UNUSED(clientData);
-
-    /* This timer shouldn't be registered unless there's work to do. */
-    serverAssert(defrag.current_stage || listLength(defrag.remaining_stages) > 0);
-
-    if (!server.active_defrag_enabled) {
-        /* Defrag has been disabled while running */
-        endDefragCycle(0);
-        return AE_NOMORE;
-    }
-
-    if (hasActiveChildProcess()) {
-        /* If there's a child process, pause the defrag, polling until the child completes. */
-        defrag.timeproc_end_time = 0; /* prevent starvation recovery */
-        return 100;
-    }
-
-    monotime starttime = getMonotonicUs();
-    int dutyCycleUs = computeDefragCycleUs();
-#if defined(DEBUG_DEFRAG_FULLY)
-    dutyCycleUs = 30*1000*1000LL; /* 30 seconds */
-#endif
-    monotime endtime = starttime + dutyCycleUs;
-    int haveMoreWork = 1;
-
-    mstime_t latency;
-    latencyStartMonitor(latency);
-
-    do {
-        if (!defrag.current_stage) {
-            defrag.current_stage = listFirst(defrag.remaining_stages);
-        }
-
-        StageDescriptor *stage = listNodeValue(defrag.current_stage);
-        doneStatus status = stage->stage_fn(stage->ctx, endtime);
-        if (status == DEFRAG_DONE) {
-            listDelNode(defrag.remaining_stages, defrag.current_stage);
-            defrag.current_stage = NULL;
-        }
-
-        haveMoreWork = (defrag.current_stage || listLength(defrag.remaining_stages) > 0);
-        /* If we've completed a stage early, and still have a standard time allotment remaining,
-         * we'll start another stage. This can happen when defrag is running infrequently, and
-         * starvation protection has increased the duty-cycle. */
-    } while (haveMoreWork && getMonotonicUs() <= endtime - DEFRAG_CYCLE_US);
-
-    latencyEndMonitor(latency);
-    latencyAddSampleIfNeeded("active-defrag-cycle", latency);
-
-    if (haveMoreWork) {
-        return computeDelayMs(endtime);
-    } else {
-        endDefragCycle(1);
-        return AE_NOMORE; /* Ends the timer proc */
-    }
-}
-
-/* During long running scripts, or while loading, there is a periodic function for handling other
- * actions. This interface allows defrag to continue running, avoiding a single long defrag step
- * after the long operation completes. */
-void defragWhileBlocked(void) {
-    /* This is called infrequently, while timers are not active. We might need to start defrag. */
-    if (!defragIsRunning()) activeDefragCycle();
-
-    if (!defragIsRunning()) return;
-
-    /* Save off the timeproc_id. If we have a normal termination, it will be cleared. */
-    long long timeproc_id = defrag.timeproc_id;
-
-    /* Simulate a single call of the timer proc */
-    long long reschedule_delay = activeDefragTimeProc(NULL, 0, NULL);
-    if (reschedule_delay == AE_NOMORE) {
-        /* If it's done, deregister the timer */
-        aeDeleteTimeEvent(server.el, timeproc_id);
-    }
-    /* Otherwise, just ignore the reschedule_delay, the timer will pop the next time that the
-     * event loop can process timers again. */
-}
-
-static void beginDefragCycle(void) {
-    serverAssert(!defragIsRunning());
-
-    moduleDefragStart();
-
-    serverAssert(defrag.remaining_stages == NULL);
-    defrag.remaining_stages = listCreate();
-    listSetFreeMethod(defrag.remaining_stages, freeDefragContext);
-
-    for (int dbid = 0; dbid < server.dbnum; dbid++) {
-        redisDb *db = &server.db[dbid];
-
-        /* Add stage for keys. */
-        defragKeysCtx *defrag_keys_ctx = zcalloc(sizeof(defragKeysCtx));
-        defrag_keys_ctx->kvstate = INIT_KVSTORE_STATE(db->keys);
-        defrag_keys_ctx->dbid = dbid;
-        addDefragStage(defragStageDbKeys, freeDefragKeysContext, defrag_keys_ctx);
-
-        /* Add stage for expires. */
-        defragKeysCtx *defrag_expires_ctx = zcalloc(sizeof(defragKeysCtx));
-        defrag_expires_ctx->kvstate = INIT_KVSTORE_STATE(db->expires);
-        defrag_expires_ctx->dbid = dbid;
-        addDefragStage(defragStageExpiresKvstore, freeDefragKeysContext, defrag_expires_ctx);
-
-        /* Add stage for subexpires. */
-        defragSubexpiresCtx *defrag_subexpires_ctx = zcalloc(sizeof(defragSubexpiresCtx));
-        defrag_subexpires_ctx->subexpires = db->subexpires;
-        defrag_subexpires_ctx->slot = ITER_SLOT_UNASSIGNED;
-        defrag_subexpires_ctx->cursor = 0;
-        defrag_subexpires_ctx->dbid = dbid;
-        addDefragStage(defragStageSubexpires, zfree, defrag_subexpires_ctx);
-    }
-
-    /* Add stage for pubsub channels. */
-    defragPubSubCtx *defrag_pubsub_ctx = zmalloc(sizeof(defragPubSubCtx));
-    defrag_pubsub_ctx->kvstate = INIT_KVSTORE_STATE(server.pubsub_channels);
-    defrag_pubsub_ctx->getPubSubChannels = getClientPubSubChannels;
-    addDefragStage(defragStagePubsubKvstore, zfree, defrag_pubsub_ctx);
-
-    /* Add stage for pubsubshard channels. */
-    defragPubSubCtx *defrag_pubsubshard_ctx = zmalloc(sizeof(defragPubSubCtx));
-    defrag_pubsubshard_ctx->kvstate = INIT_KVSTORE_STATE(server.pubsubshard_channels);
-    defrag_pubsubshard_ctx->getPubSubChannels = getClientPubSubShardChannels;
-    addDefragStage(defragStagePubsubKvstore, zfree, defrag_pubsubshard_ctx);
-
-    addDefragStage(defragLuaScripts, NULL, NULL);
-
-    /* Add stages for modules. */
-    dictIterator di;
-    dictEntry *de;
-    dictInitIterator(&di, modules);
-    while ((de = dictNext(&di)) != NULL) {
-        struct RedisModule *module = dictGetVal(de);
-        if (module->defrag_cb || module->defrag_cb_2) {
-            defragModuleCtx *ctx = zmalloc(sizeof(defragModuleCtx));
-            ctx->cursor = 0;
-            ctx->module_name = sdsnew(module->name);
-            addDefragStage(defragModuleGlobals, freeDefragModelContext, ctx);
-        }
-    }
-    dictResetIterator(&di);
-
-    defrag.current_stage = NULL;
-    defrag.start_cycle = getMonotonicUs();
-    defrag.start_defrag_hits = server.stat_active_defrag_hits;
-    defrag.start_defrag_misses = server.stat_active_defrag_misses;
-    defrag.start_frag_pct = getAllocatorFragmentation(NULL);
-    defrag.timeproc_end_time = 0;
-    defrag.timeproc_overage_us = 0;
-    defrag.timeproc_id = aeCreateTimeEvent(server.el, 0, activeDefragTimeProc, NULL, NULL);
-
-    elapsedStart(&server.stat_last_active_defrag_time);
-}
-
-void activeDefragCycle(void) {
-    if (!server.active_defrag_enabled) return;
-
-    /* Defrag gets paused while a child process is active. So there's no point in starting a new
-     * cycle or adjusting the CPU percentage for an existing cycle. */
-    if (hasActiveChildProcess()) return;
-
-    computeDefragCycles();
-
-    if (server.active_defrag_running > 0 && !defragIsRunning()) beginDefragCycle();
-}
-
-#else /* HAVE_DEFRAG */
-
-void activeDefragCycle(void) {
-    /* Not implemented yet. */
-}
-
-void *activeDefragAlloc(void *ptr) {
-    UNUSED(ptr);
-    return NULL;
-}
-
-void *activeDefragAllocRaw(size_t size) {
-    /* fallback to regular allocation */
-    return zmalloc(size);
-}
-
-void activeDefragFreeRaw(void *ptr) {
-    /* fallback to regular free */
-    zfree(ptr);
-}
-
-robj *activeDefragStringOb(robj *ob) {
-    UNUSED(ob);
-    return NULL;
-}
-
-void defragWhileBlocked(void) {
-}
-
-#endif