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[Qemu-devel] [RFC V5 31/62] qcow2: Use large L2 table for deduplication.
From: |
Benoît Canet |
Subject: |
[Qemu-devel] [RFC V5 31/62] qcow2: Use large L2 table for deduplication. |
Date: |
Wed, 16 Jan 2013 16:48:10 +0100 |
Signed-off-by: Benoit Canet <address@hidden>
---
block/qcow2-cluster.c | 2 +-
block/qcow2-refcount.c | 22 +++++++++++++++-------
block/qcow2.c | 8 ++++++--
3 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index c016e85..8ad4740 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -236,7 +236,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index,
uint64_t **table)
goto fail;
}
- memcpy(l2_table, old_table, s->cluster_size);
+ memcpy(l2_table, old_table, s->l2_size << 3);
ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &old_table);
if (ret < 0) {
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 3077a9f..f305510 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -536,12 +536,15 @@ fail:
*/
static int update_cluster_refcount(BlockDriverState *bs,
int64_t cluster_index,
- int addend)
+ int addend,
+ bool is_l2)
{
BDRVQcowState *s = bs->opaque;
int ret;
- ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend,
+ int size = is_l2 ? s->l2_size << 3 : 1;
+
+ ret = update_refcount(bs, cluster_index << s->cluster_bits, size, addend,
false);
if (ret < 0) {
return ret;
@@ -666,7 +669,7 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
if (free_in_cluster == 0)
s->free_byte_offset = 0;
if ((offset & (s->cluster_size - 1)) != 0)
- update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
+ update_cluster_refcount(bs, offset >> s->cluster_bits, 1, false);
} else {
offset = qcow2_alloc_clusters(bs, s->cluster_size);
if (offset < 0) {
@@ -676,7 +679,7 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
if ((cluster_offset + s->cluster_size) == offset) {
/* we are lucky: contiguous data */
offset = s->free_byte_offset;
- update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
+ update_cluster_refcount(bs, offset >> s->cluster_bits, 1, false);
s->free_byte_offset += size;
} else {
s->free_byte_offset = offset;
@@ -817,7 +820,10 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
} else {
uint64_t cluster_index = (offset & L2E_OFFSET_MASK) >>
s->cluster_bits;
if (addend != 0) {
- refcount = update_cluster_refcount(bs,
cluster_index, addend);
+ refcount = update_cluster_refcount(bs,
+ cluster_index,
+ addend,
+ false);
} else {
refcount = get_refcount(bs, cluster_index);
}
@@ -849,7 +855,9 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
if (addend != 0) {
- refcount = update_cluster_refcount(bs, l2_offset >>
s->cluster_bits, addend);
+ refcount = update_cluster_refcount(bs,
+ l2_offset >>
s->cluster_bits,
+ addend, true);
} else {
refcount = get_refcount(bs, l2_offset >> s->cluster_bits);
}
@@ -1145,7 +1153,7 @@ static int check_refcounts_l1(BlockDriverState *bs,
/* Mark L2 table as used */
l2_offset &= L1E_OFFSET_MASK;
inc_refcounts(bs, res, refcount_table, refcount_table_size,
- l2_offset, s->cluster_size);
+ l2_offset, s->l2_size << 3);
/* L2 tables are cluster aligned */
if (l2_offset & (s->cluster_size - 1)) {
diff --git a/block/qcow2.c b/block/qcow2.c
index 7ef9170..f70c24b 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -432,7 +432,11 @@ static int qcow2_open(BlockDriverState *bs, int flags)
s->cluster_bits = header.cluster_bits;
s->cluster_size = 1 << s->cluster_bits;
s->cluster_sectors = 1 << (s->cluster_bits - 9);
- s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
+ if (s->incompatible_features & QCOW2_INCOMPAT_DEDUP) {
+ s->l2_bits = 17; /* 64 * 16 KB L2 to compensate smaller cluster size */
+ } else {
+ s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
+ }
s->l2_size = 1 << s->l2_bits;
bs->total_sectors = header.size / 512;
s->csize_shift = (62 - (s->cluster_bits - 8));
@@ -469,7 +473,7 @@ static int qcow2_open(BlockDriverState *bs, int flags)
}
/* alloc L2 table/refcount block cache */
- s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, s->cluster_size);
+ s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, s->l2_size << 3);
s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE,
s->cluster_size);
--
1.7.10.4
- [Qemu-devel] [RFC V5 12/62] qcow2: make the deduplication forget a cluster hash when a cluster is to dedupe, (continued)
- [Qemu-devel] [RFC V5 12/62] qcow2: make the deduplication forget a cluster hash when a cluster is to dedupe, Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 17/62] qcow2: Extract qcow2_add_feature and qcow2_remove_feature., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 18/62] block: Add qemu-img dedup create option., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 22/62] qcow2: Add qcow2_dedup_is_running to probe if dedup is running., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 20/62] qcow2: Drop hash for a given cluster when dedup makes refcount > 2^16/2., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 19/62] qcow2: Add a deduplication boolean to update_refcount., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 27/62] qcow2: Add check_dedup_l2 in order to check l2 of dedup table., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 30/62] qcow2: Add lazy refcounts to deduplication to prevent qcow2_cache_set_dependency loops, Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 29/62] qcow2: Integrate SKEIN hash algorithm in deduplication., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 33/62] qemu-iotests: Filter dedup=on/off so existing tests don't break., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 31/62] qcow2: Use large L2 table for deduplication.,
Benoît Canet <=
- [Qemu-devel] [RFC V5 32/62] qcow: Set large dedup hash block size., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 34/62] qcow2: Add qcow2_dedup_init and qcow2_dedup_close., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 36/62] qcow2: Enable the deduplication feature., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 38/62] qcow2: Initialize deduplication metrics., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 35/62] qcow2: Add qcow2_co_dedup_resume to restart deduplication., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 45/62] qcow2: Count deduplication refcount overflow metric., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 42/62] qcow2: Count QCowHashNode creation metrics., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 46/62] qapi: Add support for deduplication infos in qapi-schema.json., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 47/62] block: Add deduplication metrics to BlockDriverInfo., Benoît Canet, 2013/01/16
- [Qemu-devel] [RFC V5 48/62] qcow2: Add qcow2_dedup_update_metrics to compute dedup RAM usage., Benoît Canet, 2013/01/16