mirror_zfs/module/zfs/ddt_stats.c
Rob Norris cd69ba3d49 ddt: dedup log
Adds a log/journal to dedup. At the end of txg, instead of writing the
entry directly to the ZAP, instead its adding to an in-memory tree and
appended to an on-disk object. The on-disk object is only read at
import, to reload the in-memory tree.

Lookups first go the the log tree before going to the ZAP, so
recently-used entries will remain close by in memory. This vastly
reduces overhead from dedup IO, as it will not have to do so many
read/update/write cycles on ZAP leaf nodes.

A flushing facility is added at end of txg, to push logged entries out
to the ZAP. There's actually two separate "logs" (in-memory tree and
on-disk object), one active (recieving updated entries) and one flushing
(writing out to disk). These are swapped (ie flushing begins) based on
memory used by the in-memory log trees and time since we last flushed
something.

The flushing facility monitors the amount of entries coming in and being
flushed out, and calibrates itself to try to flush enough each txg to
keep up with the ingest rate without competing too much with other IO.
Multiple tuneables are provided to control the flushing facility.

All the histograms and stats are update to accomodate the log as a
separate entry store. zdb gains knowledge of how to count them and dump
them. Documentation included!

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: iXsystems, Inc.
Closes #15895
2024-08-16 12:03:35 -07:00

339 lines
8.3 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2016 by Delphix. All rights reserved.
* Copyright (c) 2022 by Pawel Jakub Dawidek
* Copyright (c) 2023, Klara Inc.
*/
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/ddt.h>
#include <sys/ddt_impl.h>
static void
ddt_stat_generate(ddt_t *ddt, const ddt_lightweight_entry_t *ddlwe,
ddt_stat_t *dds)
{
spa_t *spa = ddt->ddt_spa;
uint64_t lsize = DDK_GET_LSIZE(&ddlwe->ddlwe_key);
uint64_t psize = DDK_GET_PSIZE(&ddlwe->ddlwe_key);
memset(dds, 0, sizeof (*dds));
for (int p = 0; p < DDT_NPHYS(ddt); p++) {
const ddt_univ_phys_t *ddp = &ddlwe->ddlwe_phys;
ddt_phys_variant_t v = DDT_PHYS_VARIANT(ddt, p);
if (ddt_phys_birth(ddp, v) == 0)
continue;
int ndvas = ddt_phys_dva_count(ddp, v,
DDK_GET_CRYPT(&ddlwe->ddlwe_key));
const dva_t *dvas = (ddt->ddt_flags & DDT_FLAG_FLAT) ?
ddp->ddp_flat.ddp_dva : ddp->ddp_trad[p].ddp_dva;
uint64_t dsize = 0;
for (int d = 0; d < ndvas; d++)
dsize += dva_get_dsize_sync(spa, &dvas[d]);
uint64_t refcnt = ddt_phys_refcnt(ddp, v);
dds->dds_blocks += 1;
dds->dds_lsize += lsize;
dds->dds_psize += psize;
dds->dds_dsize += dsize;
dds->dds_ref_blocks += refcnt;
dds->dds_ref_lsize += lsize * refcnt;
dds->dds_ref_psize += psize * refcnt;
dds->dds_ref_dsize += dsize * refcnt;
}
}
static void
ddt_stat_add(ddt_stat_t *dst, const ddt_stat_t *src)
{
dst->dds_blocks += src->dds_blocks;
dst->dds_lsize += src->dds_lsize;
dst->dds_psize += src->dds_psize;
dst->dds_dsize += src->dds_dsize;
dst->dds_ref_blocks += src->dds_ref_blocks;
dst->dds_ref_lsize += src->dds_ref_lsize;
dst->dds_ref_psize += src->dds_ref_psize;
dst->dds_ref_dsize += src->dds_ref_dsize;
}
static void
ddt_stat_sub(ddt_stat_t *dst, const ddt_stat_t *src)
{
/* This caught more during development than you might expect... */
ASSERT3U(dst->dds_blocks, >=, src->dds_blocks);
ASSERT3U(dst->dds_lsize, >=, src->dds_lsize);
ASSERT3U(dst->dds_psize, >=, src->dds_psize);
ASSERT3U(dst->dds_dsize, >=, src->dds_dsize);
ASSERT3U(dst->dds_ref_blocks, >=, src->dds_ref_blocks);
ASSERT3U(dst->dds_ref_lsize, >=, src->dds_ref_lsize);
ASSERT3U(dst->dds_ref_psize, >=, src->dds_ref_psize);
ASSERT3U(dst->dds_ref_dsize, >=, src->dds_ref_dsize);
dst->dds_blocks -= src->dds_blocks;
dst->dds_lsize -= src->dds_lsize;
dst->dds_psize -= src->dds_psize;
dst->dds_dsize -= src->dds_dsize;
dst->dds_ref_blocks -= src->dds_ref_blocks;
dst->dds_ref_lsize -= src->dds_ref_lsize;
dst->dds_ref_psize -= src->dds_ref_psize;
dst->dds_ref_dsize -= src->dds_ref_dsize;
}
void
ddt_histogram_add_entry(ddt_t *ddt, ddt_histogram_t *ddh,
const ddt_lightweight_entry_t *ddlwe)
{
ddt_stat_t dds;
int bucket;
ddt_stat_generate(ddt, ddlwe, &dds);
bucket = highbit64(dds.dds_ref_blocks) - 1;
if (bucket < 0)
return;
ddt_stat_add(&ddh->ddh_stat[bucket], &dds);
}
void
ddt_histogram_sub_entry(ddt_t *ddt, ddt_histogram_t *ddh,
const ddt_lightweight_entry_t *ddlwe)
{
ddt_stat_t dds;
int bucket;
ddt_stat_generate(ddt, ddlwe, &dds);
bucket = highbit64(dds.dds_ref_blocks) - 1;
if (bucket < 0)
return;
ddt_stat_sub(&ddh->ddh_stat[bucket], &dds);
}
void
ddt_histogram_add(ddt_histogram_t *dst, const ddt_histogram_t *src)
{
for (int h = 0; h < 64; h++)
ddt_stat_add(&dst->ddh_stat[h], &src->ddh_stat[h]);
}
void
ddt_histogram_total(ddt_stat_t *dds, const ddt_histogram_t *ddh)
{
memset(dds, 0, sizeof (*dds));
for (int h = 0; h < 64; h++)
ddt_stat_add(dds, &ddh->ddh_stat[h]);
}
boolean_t
ddt_histogram_empty(const ddt_histogram_t *ddh)
{
for (int h = 0; h < 64; h++) {
const ddt_stat_t *dds = &ddh->ddh_stat[h];
if (dds->dds_blocks == 0 &&
dds->dds_lsize == 0 &&
dds->dds_psize == 0 &&
dds->dds_dsize == 0 &&
dds->dds_ref_blocks == 0 &&
dds->dds_ref_lsize == 0 &&
dds->dds_ref_psize == 0 &&
dds->dds_ref_dsize == 0)
continue;
return (B_FALSE);
}
return (B_TRUE);
}
void
ddt_get_dedup_object_stats(spa_t *spa, ddt_object_t *ddo_total)
{
memset(ddo_total, 0, sizeof (*ddo_total));
for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
ddt_t *ddt = spa->spa_ddt[c];
if (!ddt)
continue;
for (ddt_type_t type = 0; type < DDT_TYPES; type++) {
for (ddt_class_t class = 0; class < DDT_CLASSES;
class++) {
dmu_object_info_t doi;
uint64_t cnt;
int err;
/*
* These stats were originally calculated
* during ddt_object_load().
*/
err = ddt_object_info(ddt, type, class, &doi);
if (err != 0)
continue;
err = ddt_object_count(ddt, type, class, &cnt);
if (err != 0)
continue;
ddt_object_t *ddo =
&ddt->ddt_object_stats[type][class];
ddo->ddo_count = cnt;
ddo->ddo_dspace =
doi.doi_physical_blocks_512 << 9;
ddo->ddo_mspace = doi.doi_fill_count *
doi.doi_data_block_size;
ddo_total->ddo_count += ddo->ddo_count;
ddo_total->ddo_dspace += ddo->ddo_dspace;
ddo_total->ddo_mspace += ddo->ddo_mspace;
}
}
ddt_object_t *ddo = &ddt->ddt_log_stats;
ddo_total->ddo_count += ddo->ddo_count;
ddo_total->ddo_dspace += ddo->ddo_dspace;
ddo_total->ddo_mspace += ddo->ddo_mspace;
}
/*
* This returns raw counts (not averages). One of the consumers,
* print_dedup_stats(), historically has expected raw counts.
*/
spa->spa_dedup_dsize = ddo_total->ddo_dspace;
}
uint64_t
ddt_get_ddt_dsize(spa_t *spa)
{
ddt_object_t ddo_total;
/* recalculate after each txg sync */
if (spa->spa_dedup_dsize == ~0ULL)
ddt_get_dedup_object_stats(spa, &ddo_total);
return (spa->spa_dedup_dsize);
}
void
ddt_get_dedup_histogram(spa_t *spa, ddt_histogram_t *ddh)
{
for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
ddt_t *ddt = spa->spa_ddt[c];
if (!ddt)
continue;
for (ddt_type_t type = 0; type < DDT_TYPES; type++) {
for (ddt_class_t class = 0; class < DDT_CLASSES;
class++) {
ddt_histogram_add(ddh,
&ddt->ddt_histogram_cache[type][class]);
}
}
ddt_histogram_add(ddh, &ddt->ddt_log_histogram);
}
}
void
ddt_get_dedup_stats(spa_t *spa, ddt_stat_t *dds_total)
{
ddt_histogram_t *ddh_total;
ddh_total = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
ddt_get_dedup_histogram(spa, ddh_total);
ddt_histogram_total(dds_total, ddh_total);
kmem_free(ddh_total, sizeof (ddt_histogram_t));
}
uint64_t
ddt_get_dedup_dspace(spa_t *spa)
{
ddt_stat_t dds_total;
if (spa->spa_dedup_dspace != ~0ULL)
return (spa->spa_dedup_dspace);
memset(&dds_total, 0, sizeof (ddt_stat_t));
/* Calculate and cache the stats */
ddt_get_dedup_stats(spa, &dds_total);
spa->spa_dedup_dspace = dds_total.dds_ref_dsize - dds_total.dds_dsize;
return (spa->spa_dedup_dspace);
}
uint64_t
ddt_get_pool_dedup_ratio(spa_t *spa)
{
ddt_stat_t dds_total = { 0 };
ddt_get_dedup_stats(spa, &dds_total);
if (dds_total.dds_dsize == 0)
return (100);
return (dds_total.dds_ref_dsize * 100 / dds_total.dds_dsize);
}
int
ddt_get_pool_dedup_cached(spa_t *spa, uint64_t *psize)
{
uint64_t l1sz, l1tot, l2sz, l2tot;
int err = 0;
l1tot = l2tot = 0;
*psize = 0;
for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
ddt_t *ddt = spa->spa_ddt[c];
if (ddt == NULL)
continue;
for (ddt_type_t type = 0; type < DDT_TYPES; type++) {
for (ddt_class_t class = 0; class < DDT_CLASSES;
class++) {
err = dmu_object_cached_size(ddt->ddt_os,
ddt->ddt_object[type][class], &l1sz, &l2sz);
if (err != 0)
return (err);
l1tot += l1sz;
l2tot += l2sz;
}
}
}
*psize = l1tot + l2tot;
return (err);
}