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[Qemu-devel] [PATCH 2/2] qcow2: Prefer 'entries' over 'size' during cach
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH 2/2] qcow2: Prefer 'entries' over 'size' during cache creation |
Date: |
Tue, 13 Feb 2018 17:33:24 -0600 |
Using 'size' for anything other than bytes is difficult to
reason about; let's rename entries related to the number of
entries in a cache accordingly.
Signed-off-by: Eric Blake <address@hidden>
---
block/qcow2.h | 4 ++--
block/qcow2.c | 21 +++++++++++----------
2 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/block/qcow2.h b/block/qcow2.h
index 883802241fb..0daf8e6d6f8 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -68,10 +68,10 @@
#define MAX_CLUSTER_BITS 21
/* Must be at least 2 to cover COW */
-#define MIN_L2_CACHE_SIZE 2 /* cache entries */
+#define MIN_L2_CACHE_ENTRIES 2
/* Must be at least 4 to cover all cases of refcount table growth */
-#define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
+#define MIN_REFCOUNT_CACHE_ENTRIES 4
/* Whichever is more */
#define DEFAULT_L2_CACHE_CLUSTERS 8 /* clusters */
diff --git a/block/qcow2.c b/block/qcow2.c
index 288b5299d80..f25c33df1d1 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -843,6 +843,7 @@ static int qcow2_update_options_prepare(BlockDriverState
*bs,
const char *opt_overlap_check, *opt_overlap_check_template;
int overlap_check_template = 0;
uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size;
+ uint64_t l2_cache_entries, refcount_cache_entries;
int i;
const char *encryptfmt;
QDict *encryptopts = NULL;
@@ -869,21 +870,21 @@ static int qcow2_update_options_prepare(BlockDriverState
*bs,
goto fail;
}
- l2_cache_size /= l2_cache_entry_size;
- if (l2_cache_size < MIN_L2_CACHE_SIZE) {
- l2_cache_size = MIN_L2_CACHE_SIZE;
+ l2_cache_entries = l2_cache_size / l2_cache_entry_size;
+ if (l2_cache_entries < MIN_L2_CACHE_ENTRIES) {
+ l2_cache_entries = MIN_L2_CACHE_ENTRIES;
}
- if (l2_cache_size > INT_MAX) {
+ if (l2_cache_entries > INT_MAX) {
error_setg(errp, "L2 cache size too big");
ret = -EINVAL;
goto fail;
}
- refcount_cache_size /= s->cluster_size;
- if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) {
- refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE;
+ refcount_cache_entries = refcount_cache_size / s->cluster_size;
+ if (refcount_cache_entries < MIN_REFCOUNT_CACHE_ENTRIES) {
+ refcount_cache_entries = MIN_REFCOUNT_CACHE_ENTRIES;
}
- if (refcount_cache_size > INT_MAX) {
+ if (refcount_cache_entries > INT_MAX) {
error_setg(errp, "Refcount cache size too big");
ret = -EINVAL;
goto fail;
@@ -908,9 +909,9 @@ static int qcow2_update_options_prepare(BlockDriverState
*bs,
}
r->l2_slice_size = l2_cache_entry_size / sizeof(uint64_t);
- r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size,
+ r->l2_table_cache = qcow2_cache_create(bs, l2_cache_entries,
l2_cache_entry_size);
- r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size,
+ r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_entries,
s->cluster_size);
if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) {
error_setg(errp, "Could not allocate metadata caches");
--
2.14.3