From 925dd0e487ee0a7910370810e0167cc4efa198e0 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Thu, 19 Dec 2024 19:42:54 -0500 Subject: [PATCH v4 2/2] Eagerly scan all-visible pages to amortize aggressive vacuum Introduce eager scanning normal vacuums, in which vacuum scans some of the all-visible but not all-frozen pages in the relation to amortize the cost of an aggressive vacuum. Because the goal is to freeze these all-visible pages, all-visible pages that are eagerly scanned and set all-frozen in the visibility map are considered successful eager scans and those not frozen are considered failed eager scans. If too many eager scans fail in a row, eager scanning is temporarily suspended until a later portion of the relation. To effectively amortize aggressive vacuums, we cap the number of successes as well. Once we reach the maximum number of blocks successfully eager scanned and frozen, eager scanning is permanently disabled for the current vacuum. Original design idea from Robert Haas, with enhancements from Andres Freund, Tomas Vondra, and me Author: Melanie Plageman Reviewed-by: Andres Freund, Robert Haas, Robert Treat, Bilal Yavuz Discussion: https://postgr.es/m/flat/CAAKRu_ZF_KCzZuOrPrOqjGVe8iRVWEAJSpzMgRQs%3D5-v84cXUg%40mail.gmail.com --- src/backend/access/heap/vacuumlazy.c | 379 +++++++++++++++++++++++++-- 1 file changed, 352 insertions(+), 27 deletions(-) diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index f8edbab21d2..0318650a2bf 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -30,10 +30,47 @@ * to the end, skipping pages as permitted by their visibility status, vacuum * options, and the eagerness level of the vacuum. * - * When page skipping is enabled, non-aggressive vacuums may skip scanning - * pages that are marked all-visible in the visibility map. We may choose not - * to skip pages if the range of skippable pages is below - * SKIP_PAGES_THRESHOLD. + * Vacuums are either aggressive or normal. Aggressive vacuums must scan every + * unfrozen tuple in order to advance relfrozenxid and avoid transaction ID + * wraparound. Normal vacuums may eagerly scan otherwise skippable pages for + * one of two reasons: + * + * When page skipping is not disabled, a normal vacuum may skip scanning pages + * that are marked all-visible (and even all-frozen) in the visibility map if + * the range of skippable pages is below SKIP_PAGES_THRESHOLD. This is + * primarily for the benefit of kernel readahead (see comment in + * heap_vac_scan_next_block()). + * + * A normal vacuum may also scan skippable pages in an effort to freeze them + * and decrease the backlog of all-visible but not all-frozen pages that have + * to be processed by the next aggressive vacuum. These are referred to as + * eagerly scanned pages. Pages scanned due to SKIP_PAGES_THRESHOLD do not + * count as eagerly scanned pages. + * + * Normal vacuums count all-visible pages eagerly scanned as a success when + * they are able to set them all-frozen in the VM and as a failure when they + * are not able to set them all-frozen. + * + * Because we want to amortize the overhead of freezing pages over multiple + * vacuums, normal vacuums cap the number of successful eager scans to + * EAGER_SCAN_SUCCESS_RATE of the number of all-visible but not all-frozen + * pages at the beginning of the vacuum. Once the success cap has been hit, + * eager scanning is permanently disabled. + * + * Success is a global cap because we don't want to limit our successes if old + * data happens to be concentrated in a particular part of the table. This is + * especially likely to happen for append-mostly workloads where the oldest + * data is at the beginning of the unfrozen portion of the relation. + * + * On the assumption that different regions of the table are likely to contain + * similarly aged data, normal vacuums use a localized eager scan failure cap + * instead of a global cap for the whole relation. The failure count is reset + * for each region of the table -- comprised of EAGER_SCAN_REGION_SIZE blocks. + * In each region, we tolerate EAGER_SCAN_MAX_FAILS_PER_REGION before + * suspending eager scanning until the end of the region. + * + * Aggressive vacuums must examine every unfrozen tuple and are thus not + * subject to failure or success caps when eagerly scanning all-visible pages. * * Once vacuum has decided to scan a given block, it must read in the block * and obtain a cleanup lock to prune tuples on the page. A non-aggressive @@ -88,6 +125,7 @@ #include "commands/progress.h" #include "commands/vacuum.h" #include "common/int.h" +#include "common/pg_prng.h" #include "executor/instrument.h" #include "miscadmin.h" #include "pgstat.h" @@ -173,6 +211,29 @@ typedef enum VACUUM_ERRCB_PHASE_TRUNCATE, } VacErrPhase; +/* + * Normal vacuums may eagerly scan some all-visible but not all-frozen pages. + * Since our goal is to freeze these pages, an eager scan that fails to set + * the page all-frozen in the VM is considered to have "failed". + * + * On the assumption that different regions of the table tend to have + * similarly aged data, once we fail to freeze EAGER_SCAN_MAX_FAILS_PER_REGION + * blocks in a region of size EAGER_SCAN_REGION_SIZE, we suspend eager + * scanning until vacuum has progressed to another region of the table with + * potentially older data. + */ +#define EAGER_SCAN_REGION_SIZE 4096 +#define EAGER_SCAN_MAX_FAILS_PER_REGION 128 + +/* + * An eager scan of a page that is set all-frozen in the VM is considered + * "successful". To spread out eager scanning across multiple normal vacuums, + * we limit the number of successful eager page scans. The maximum number of + * successful eager page scans is calculated as a ratio of the all-visible but + * not all-frozen pages at the beginning of the vacuum. + */ +#define EAGER_SCAN_SUCCESS_RATE 0.2 + typedef struct LVRelState { /* Target heap relation and its indexes */ @@ -229,6 +290,13 @@ typedef struct LVRelState BlockNumber rel_pages; /* total number of pages */ BlockNumber scanned_pages; /* # pages examined (not skipped via VM) */ + + /* + * Count of all-visible blocks eagerly scanned (for logging only). This + * does not include skippable blocks scanned due to SKIP_PAGES_THRESHOLD. + */ + BlockNumber eager_scanned_pages; + BlockNumber removed_pages; /* # pages removed by relation truncation */ BlockNumber new_frozen_tuple_pages; /* # pages with newly frozen tuples */ @@ -270,9 +338,46 @@ typedef struct LVRelState BlockNumber current_block; /* last block returned */ BlockNumber next_unskippable_block; /* next unskippable block */ bool next_unskippable_allvis; /* its visibility status */ + bool next_unskippable_eager_scanned; /* if it was eager scanned */ Buffer next_unskippable_vmbuffer; /* buffer containing its VM bit */ + + /* State related to managing eager scanning of all-visible pages */ + + /* + * A normal vacuum that has failed to freeze too many eagerly scanned + * blocks in a row suspends eager scanning. next_eager_scan_region_start + * is the block number of the first block eligible for resumed eager + * scanning. + * + * When eager scanning is permanently disabled, either initially + * (including for aggressive vacuum) or due to hitting the success limit, + * this is set to InvalidBlockNumber. + */ + BlockNumber next_eager_scan_region_start; + + /* + * The remaining number of blocks a normal vacuum will consider eager + * scanning. When eager scanning is enabled, this is initialized to + * EAGER_SCAN_SUCCESS_RATE of the total number of all-visible but not + * all-frozen pages. For each eager scan success, this is decremented. + * Once it hits 0, eager scanning is permanently disabled. It is + * initialized to 0 if eager scanning starts out disabled (including for + * aggressive vacuum). + */ + BlockNumber eager_scan_remaining_successes; + + /* + * The number of eagerly scanned blocks vacuum failed to freeze (due to + * age) in the current eager scan region. Vacuum resets it to + * EAGER_SCAN_MAX_FAILS_PER_REGION each time it enters a new region of the + * relation. If eager_scan_remaining_fails hits 0, eager scanning is + * suspended until the next region. It is also 0 if eager scanning has + * been permanently disabled. + */ + BlockNumber eager_scan_remaining_fails; } LVRelState; + /* Struct for saving and restoring vacuum error information. */ typedef struct LVSavedErrInfo { @@ -284,8 +389,10 @@ typedef struct LVSavedErrInfo /* non-export function prototypes */ static void lazy_scan_heap(LVRelState *vacrel); +static void heap_vacuum_eager_scan_setup(LVRelState *vacrel); static bool heap_vac_scan_next_block(LVRelState *vacrel, BlockNumber *blkno, - bool *all_visible_according_to_vm); + bool *all_visible_according_to_vm, + bool *was_eager_scanned); static void find_next_unskippable_block(LVRelState *vacrel, bool *skipsallvis); static bool lazy_scan_new_or_empty(LVRelState *vacrel, Buffer buf, BlockNumber blkno, Page page, @@ -293,7 +400,7 @@ static bool lazy_scan_new_or_empty(LVRelState *vacrel, Buffer buf, static void lazy_scan_prune(LVRelState *vacrel, Buffer buf, BlockNumber blkno, Page page, Buffer vmbuffer, bool all_visible_according_to_vm, - bool *has_lpdead_items); + bool *has_lpdead_items, bool *vm_page_frozen); static bool lazy_scan_noprune(LVRelState *vacrel, Buffer buf, BlockNumber blkno, Page page, bool *has_lpdead_items); @@ -335,6 +442,113 @@ static void restore_vacuum_error_info(LVRelState *vacrel, const LVSavedErrInfo *saved_vacrel); + +/* + * Helper to set up the eager scanning state for vacuuming a single relation. + * Initializes the eager scan management related members of the LVRelState. + * + * Caller provides whether or not an aggressive vacuum is required due to + * vacuum options or for relfrozenxid/relminmxid advancement. + */ +static void +heap_vacuum_eager_scan_setup(LVRelState *vacrel) +{ + uint32 randseed; + BlockNumber allvisible; + BlockNumber allfrozen; + float first_region_ratio; + bool oldest_unfrozen_requires_freeze = false; + + /* + * Initialize eager scan management fields to their disabled values. + * Aggressive vacuums, normal vacuums of small tables, and normal vacuums + * of tables without old enough tuples will have eager scanning disabled. + */ + vacrel->next_eager_scan_region_start = InvalidBlockNumber; + vacrel->eager_scan_remaining_fails = 0; + vacrel->eager_scan_remaining_successes = 0; + + /* + * The caller will have determined whether or not an aggressive vacuum is + * required by either the vacuum parameters or the relative age of the + * oldest unfrozen transaction IDs. An aggressive vacuum must scan every + * all-visible page to safely advance the relfrozenxid and/or relminmxid, + * so scanning all-visible pages is not considered eager. + */ + if (vacrel->aggressive) + return; + + /* + * If the relation is smaller than a single region, we won't bother eager + * scanning it, as a future aggressive vacuum shouldn't take very long + * anyway so there is no point in amortization. + */ + if (vacrel->rel_pages < EAGER_SCAN_REGION_SIZE) + return; + + /* + * We only want to enable eager scanning if we are likely to be able to + * freeze some of the pages in the relation. We are only guaranteed to + * freeze a freezable page if some of the tuples require freezing. Tuples + * require freezing if any of their xids precede the freeze limit or + * multixact cutoff. So, if the oldest unfrozen xid + * (relfrozenxid/relminmxid) does not precede the freeze cutoff, we won't + * find tuples requiring freezing. + */ + if (TransactionIdIsNormal(vacrel->cutoffs.relfrozenxid) && + TransactionIdPrecedesOrEquals(vacrel->cutoffs.relfrozenxid, + vacrel->cutoffs.FreezeLimit)) + oldest_unfrozen_requires_freeze = true; + + if (!oldest_unfrozen_requires_freeze && + MultiXactIdIsValid(vacrel->cutoffs.relminmxid) && + MultiXactIdPrecedesOrEquals(vacrel->cutoffs.relminmxid, + vacrel->cutoffs.MultiXactCutoff)) + oldest_unfrozen_requires_freeze = true; + + if (!oldest_unfrozen_requires_freeze) + return; + + /* + * We are not required to do an aggressive vacuum and we have met the + * criteria to eagerly scan some pages. + */ + + /* + * Our success cap is EAGER_SCAN_SUCCESS_RATE of the number of all-visible + * but not all-frozen blocks in the relation. + */ + visibilitymap_count(vacrel->rel, &allvisible, &allfrozen); + + vacrel->eager_scan_remaining_successes = + (BlockNumber) (EAGER_SCAN_SUCCESS_RATE * + (allvisible - allfrozen)); + + /* If the table is entirely frozen, eager scanning is disabled. */ + if (vacrel->eager_scan_remaining_successes == 0) + return; + + /* + * Now calculate the eager scan start block. Start at a random spot + * somewhere within the first eager scan region. This avoids eager + * scanning and failing to freeze the exact same blocks each vacuum of the + * relation. + */ + randseed = pg_prng_uint32(&pg_global_prng_state); + + vacrel->next_eager_scan_region_start = randseed % EAGER_SCAN_REGION_SIZE; + + /* + * The first region will be smaller than subsequent regions. As such, + * adjust the eager scan failures tolerated for this region. + */ + first_region_ratio = 1 - (float) vacrel->next_eager_scan_region_start / + EAGER_SCAN_REGION_SIZE; + + vacrel->eager_scan_remaining_fails = EAGER_SCAN_MAX_FAILS_PER_REGION * + first_region_ratio; +} + /* * heap_vacuum_rel() -- perform VACUUM for one heap relation * @@ -463,6 +677,7 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, /* Initialize page counters explicitly (be tidy) */ vacrel->scanned_pages = 0; + vacrel->eager_scanned_pages = 0; vacrel->removed_pages = 0; vacrel->new_frozen_tuple_pages = 0; vacrel->lpdead_item_pages = 0; @@ -488,6 +703,7 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, vacrel->vm_new_visible_pages = 0; vacrel->vm_new_visible_frozen_pages = 0; vacrel->vm_new_frozen_pages = 0; + vacrel->rel_pages = orig_rel_pages = RelationGetNumberOfBlocks(rel); /* * Get cutoffs that determine which deleted tuples are considered DEAD, @@ -506,11 +722,16 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, * to increase the number of dead tuples it can prune away.) */ vacrel->aggressive = vacuum_get_cutoffs(rel, params, &vacrel->cutoffs); - vacrel->rel_pages = orig_rel_pages = RelationGetNumberOfBlocks(rel); vacrel->vistest = GlobalVisTestFor(rel); /* Initialize state used to track oldest extant XID/MXID */ vacrel->NewRelfrozenXid = vacrel->cutoffs.OldestXmin; vacrel->NewRelminMxid = vacrel->cutoffs.OldestMxact; + + /* + * Initialize state related to tracking all-visible page skipping. This is + * very important to determine whether or not it is safe to advance the + * relfrozenxid. + */ vacrel->skippedallvis = false; skipwithvm = true; if (params->options & VACOPT_DISABLE_PAGE_SKIPPING) @@ -525,6 +746,13 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, vacrel->skipwithvm = skipwithvm; + /* + * Next set up eager scan tracking state. This must happen after + * determining whether or not the vacuum must be aggressive, because only + * normal vacuums are considered to eagerly scan pages. + */ + heap_vacuum_eager_scan_setup(vacrel); + if (verbose) { if (vacrel->aggressive) @@ -719,12 +947,14 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, vacrel->relnamespace, vacrel->relname, vacrel->num_index_scans); - appendStringInfo(&buf, _("pages: %u removed, %u remain, %u scanned (%.2f%% of total)\n"), + appendStringInfo(&buf, _("pages: %u removed, %u remain, %u scanned (%.2f%% of total), %u eager scanned\n"), vacrel->removed_pages, new_rel_pages, vacrel->scanned_pages, orig_rel_pages == 0 ? 100.0 : - 100.0 * vacrel->scanned_pages / orig_rel_pages); + 100.0 * vacrel->scanned_pages / + orig_rel_pages, + vacrel->eager_scanned_pages); appendStringInfo(&buf, _("tuples: %lld removed, %lld remain, %lld are dead but not yet removable\n"), (long long) vacrel->tuples_deleted, @@ -895,8 +1125,10 @@ lazy_scan_heap(LVRelState *vacrel) BlockNumber rel_pages = vacrel->rel_pages, blkno, next_fsm_block_to_vacuum = 0; - bool all_visible_according_to_vm; - + bool all_visible_according_to_vm, + was_eager_scanned = false; + BlockNumber orig_eager_scan_success_limit = + vacrel->eager_scan_remaining_successes; /* for logging */ Buffer vmbuffer = InvalidBuffer; const int initprog_index[] = { PROGRESS_VACUUM_PHASE, @@ -915,13 +1147,16 @@ lazy_scan_heap(LVRelState *vacrel) vacrel->current_block = InvalidBlockNumber; vacrel->next_unskippable_block = InvalidBlockNumber; vacrel->next_unskippable_allvis = false; + vacrel->next_unskippable_eager_scanned = false; vacrel->next_unskippable_vmbuffer = InvalidBuffer; - while (heap_vac_scan_next_block(vacrel, &blkno, &all_visible_according_to_vm)) + while (heap_vac_scan_next_block(vacrel, &blkno, &all_visible_according_to_vm, + &was_eager_scanned)) { Buffer buf; Page page; bool has_lpdead_items; + bool vm_page_frozen = false; bool got_cleanup_lock = false; vacrel->scanned_pages++; @@ -1049,7 +1284,48 @@ lazy_scan_heap(LVRelState *vacrel) if (got_cleanup_lock) lazy_scan_prune(vacrel, buf, blkno, page, vmbuffer, all_visible_according_to_vm, - &has_lpdead_items); + &has_lpdead_items, &vm_page_frozen); + + /* + * Count an eagerly scanned page as a failure or a success. + */ + if (was_eager_scanned) + { + if (vm_page_frozen) + { + Assert(vacrel->eager_scan_remaining_successes > 0); + vacrel->eager_scan_remaining_successes--; + + if (vacrel->eager_scan_remaining_successes == 0) + { + /* + * An aggressive vacuum is not considered to eagerly scan + * pages, so it should never get here. + */ + Assert(!vacrel->aggressive); + + /* + * If we hit our success limit, there is no need to + * eagerly scan any additional pages. Permanently disable + * eager scanning by setting the other eager scan + * management fields to their disabled values as well. + */ + vacrel->eager_scan_remaining_fails = 0; + vacrel->next_eager_scan_region_start = InvalidBlockNumber; + + ereport(INFO, + (errmsg("Vacuum successfully froze %u eager scanned blocks of \"%s.%s.%s\". Now disabling eager scanning.", + orig_eager_scan_success_limit, + vacrel->dbname, vacrel->relnamespace, + vacrel->relname))); + } + } + else + { + Assert(vacrel->eager_scan_remaining_fails > 0); + vacrel->eager_scan_remaining_fails--; + } + } /* * Now drop the buffer lock and, potentially, update the FSM. @@ -1149,7 +1425,9 @@ lazy_scan_heap(LVRelState *vacrel) * * The block number and visibility status of the next block to process are set * in *blkno and *all_visible_according_to_vm. The return value is false if - * there are no further blocks to process. + * there are no further blocks to process. If the block is being eagerly + * scanned, was_eager_scanned is set so that the caller can count whether or + * not an eager scanned page is successfully frozen. * * vacrel is an in/out parameter here. Vacuum options and information about * the relation are read. vacrel->skippedallvis is set if we skip a block @@ -1159,13 +1437,16 @@ lazy_scan_heap(LVRelState *vacrel) */ static bool heap_vac_scan_next_block(LVRelState *vacrel, BlockNumber *blkno, - bool *all_visible_according_to_vm) + bool *all_visible_according_to_vm, + bool *was_eager_scanned) { BlockNumber next_block; /* relies on InvalidBlockNumber + 1 overflowing to 0 on first call */ next_block = vacrel->current_block + 1; + *was_eager_scanned = false; + /* Have we reached the end of the relation? */ if (next_block >= vacrel->rel_pages) { @@ -1238,6 +1519,9 @@ heap_vac_scan_next_block(LVRelState *vacrel, BlockNumber *blkno, *blkno = vacrel->current_block = next_block; *all_visible_according_to_vm = vacrel->next_unskippable_allvis; + *was_eager_scanned = vacrel->next_unskippable_eager_scanned; + if (*was_eager_scanned) + vacrel->eager_scanned_pages++; return true; } } @@ -1261,11 +1545,12 @@ find_next_unskippable_block(LVRelState *vacrel, bool *skipsallvis) BlockNumber rel_pages = vacrel->rel_pages; BlockNumber next_unskippable_block = vacrel->next_unskippable_block + 1; Buffer next_unskippable_vmbuffer = vacrel->next_unskippable_vmbuffer; + bool next_unskippable_eager_scanned = false; bool next_unskippable_allvis; *skipsallvis = false; - for (;;) + for (;; next_unskippable_block++) { uint8 mapbits = visibilitymap_get_status(vacrel->rel, next_unskippable_block, @@ -1273,6 +1558,17 @@ find_next_unskippable_block(LVRelState *vacrel, bool *skipsallvis) next_unskippable_allvis = (mapbits & VISIBILITYMAP_ALL_VISIBLE) != 0; + /* + * At the start of each eager scan region, normal vacuums with eager + * scanning enabled reset the failure counter, allowing them to resume + * eager scanning if it had been suspended in the previous region. + */ + if (next_unskippable_block >= vacrel->next_eager_scan_region_start) + { + vacrel->eager_scan_remaining_fails = EAGER_SCAN_MAX_FAILS_PER_REGION; + vacrel->next_eager_scan_region_start += EAGER_SCAN_REGION_SIZE; + } + /* * A block is unskippable if it is not all visible according to the * visibility map. @@ -1305,24 +1601,34 @@ find_next_unskippable_block(LVRelState *vacrel, bool *skipsallvis) * all-visible. They may still skip all-frozen pages, which can't * contain XIDs < OldestXmin (XIDs that aren't already frozen by now). */ - if ((mapbits & VISIBILITYMAP_ALL_FROZEN) == 0) - { - if (vacrel->aggressive) - break; + if (mapbits & VISIBILITYMAP_ALL_FROZEN) + continue; - /* - * All-visible block is safe to skip in non-aggressive case. But - * remember that the final range contains such a block for later. - */ - *skipsallvis = true; + /* + * Aggressive vacuums cannot skip all-visible pages that are not also + * all-frozen. Normal vacuums with eager scanning enabled only skip + * such pages if they have hit the failure limit for the current eager + * scan region. + */ + if (vacrel->aggressive || + vacrel->eager_scan_remaining_fails > 0) + { + if (!vacrel->aggressive) + next_unskippable_eager_scanned = true; + break; } - next_unskippable_block++; + /* + * All-visible blocks are safe to skip in a normal vacuum. But + * remember that the final range contains such a block for later. + */ + *skipsallvis = true; } /* write the local variables back to vacrel */ vacrel->next_unskippable_block = next_unskippable_block; vacrel->next_unskippable_allvis = next_unskippable_allvis; + vacrel->next_unskippable_eager_scanned = next_unskippable_eager_scanned; vacrel->next_unskippable_vmbuffer = next_unskippable_vmbuffer; } @@ -1353,6 +1659,10 @@ find_next_unskippable_block(LVRelState *vacrel, bool *skipsallvis) * lazy_scan_prune (or lazy_scan_noprune). Otherwise returns true, indicating * that lazy_scan_heap is done processing the page, releasing lock on caller's * behalf. + * + * No vm_page_frozen output parameter (like what is passed to + * lazy_scan_prune()) is passed here because empty pages are always frozen and + * thus could never be eager scanned. */ static bool lazy_scan_new_or_empty(LVRelState *vacrel, Buffer buf, BlockNumber blkno, @@ -1492,6 +1802,10 @@ cmpOffsetNumbers(const void *a, const void *b) * * *has_lpdead_items is set to true or false depending on whether, upon return * from this function, any LP_DEAD items are still present on the page. + * + * *vm_page_frozen is set to true if the page is set all-frozen in the VM. The + * caller currently only uses this for determining whether an eagerly scanned + * page was successfully set all-frozen. */ static void lazy_scan_prune(LVRelState *vacrel, @@ -1500,7 +1814,8 @@ lazy_scan_prune(LVRelState *vacrel, Page page, Buffer vmbuffer, bool all_visible_according_to_vm, - bool *has_lpdead_items) + bool *has_lpdead_items, + bool *vm_page_frozen) { Relation rel = vacrel->rel; PruneFreezeResult presult; @@ -1652,11 +1967,17 @@ lazy_scan_prune(LVRelState *vacrel, { vacrel->vm_new_visible_pages++; if (presult.all_frozen) + { vacrel->vm_new_visible_frozen_pages++; + *vm_page_frozen = true; + } } else if ((old_vmbits & VISIBILITYMAP_ALL_FROZEN) == 0 && presult.all_frozen) + { vacrel->vm_new_frozen_pages++; + *vm_page_frozen = true; + } } /* @@ -1744,6 +2065,7 @@ lazy_scan_prune(LVRelState *vacrel, { vacrel->vm_new_visible_pages++; vacrel->vm_new_visible_frozen_pages++; + *vm_page_frozen = true; } /* @@ -1751,7 +2073,10 @@ lazy_scan_prune(LVRelState *vacrel, * above, so we don't need to test the value of old_vmbits. */ else + { vacrel->vm_new_frozen_pages++; + *vm_page_frozen = true; + } } } -- 2.34.1