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authorDon Dugger <n0ano@n0ano.com>2016-06-03 03:33:22 +0000
committerGerrit Code Review <gerrit@172.30.200.206>2016-06-03 03:33:23 +0000
commitda27230f80795d0028333713f036d44c53cb0e68 (patch)
treeb3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/block/qcow2-cache.c
parent0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff)
parent437fd90c0250dee670290f9b714253671a990160 (diff)
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/block/qcow2-cache.c')
-rw-r--r--qemu/block/qcow2-cache.c85
1 files changed, 73 insertions, 12 deletions
diff --git a/qemu/block/qcow2-cache.c b/qemu/block/qcow2-cache.c
index 53b8afc3d..0fe8edae4 100644
--- a/qemu/block/qcow2-cache.c
+++ b/qemu/block/qcow2-cache.c
@@ -22,6 +22,13 @@
* THE SOFTWARE.
*/
+/* Needed for CONFIG_MADVISE */
+#include "qemu/osdep.h"
+
+#if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
+#include <sys/mman.h>
+#endif
+
#include "block/block_int.h"
#include "qemu-common.h"
#include "qcow2.h"
@@ -29,9 +36,9 @@
typedef struct Qcow2CachedTable {
int64_t offset;
- bool dirty;
uint64_t lru_counter;
int ref;
+ bool dirty;
} Qcow2CachedTable;
struct Qcow2Cache {
@@ -41,34 +48,85 @@ struct Qcow2Cache {
bool depends_on_flush;
void *table_array;
uint64_t lru_counter;
+ uint64_t cache_clean_lru_counter;
};
static inline void *qcow2_cache_get_table_addr(BlockDriverState *bs,
Qcow2Cache *c, int table)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
return (uint8_t *) c->table_array + (size_t) table * s->cluster_size;
}
static inline int qcow2_cache_get_table_idx(BlockDriverState *bs,
Qcow2Cache *c, void *table)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
ptrdiff_t table_offset = (uint8_t *) table - (uint8_t *) c->table_array;
int idx = table_offset / s->cluster_size;
assert(idx >= 0 && idx < c->size && table_offset % s->cluster_size == 0);
return idx;
}
+static void qcow2_cache_table_release(BlockDriverState *bs, Qcow2Cache *c,
+ int i, int num_tables)
+{
+#if QEMU_MADV_DONTNEED != QEMU_MADV_INVALID
+ BDRVQcow2State *s = bs->opaque;
+ void *t = qcow2_cache_get_table_addr(bs, c, i);
+ int align = getpagesize();
+ size_t mem_size = (size_t) s->cluster_size * num_tables;
+ size_t offset = QEMU_ALIGN_UP((uintptr_t) t, align) - (uintptr_t) t;
+ size_t length = QEMU_ALIGN_DOWN(mem_size - offset, align);
+ if (length > 0) {
+ qemu_madvise((uint8_t *) t + offset, length, QEMU_MADV_DONTNEED);
+ }
+#endif
+}
+
+static inline bool can_clean_entry(Qcow2Cache *c, int i)
+{
+ Qcow2CachedTable *t = &c->entries[i];
+ return t->ref == 0 && !t->dirty && t->offset != 0 &&
+ t->lru_counter <= c->cache_clean_lru_counter;
+}
+
+void qcow2_cache_clean_unused(BlockDriverState *bs, Qcow2Cache *c)
+{
+ int i = 0;
+ while (i < c->size) {
+ int to_clean = 0;
+
+ /* Skip the entries that we don't need to clean */
+ while (i < c->size && !can_clean_entry(c, i)) {
+ i++;
+ }
+
+ /* And count how many we can clean in a row */
+ while (i < c->size && can_clean_entry(c, i)) {
+ c->entries[i].offset = 0;
+ c->entries[i].lru_counter = 0;
+ i++;
+ to_clean++;
+ }
+
+ if (to_clean > 0) {
+ qcow2_cache_table_release(bs, c, i - to_clean, to_clean);
+ }
+ }
+
+ c->cache_clean_lru_counter = c->lru_counter;
+}
+
Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
Qcow2Cache *c;
c = g_new0(Qcow2Cache, 1);
c->size = num_tables;
c->entries = g_try_new0(Qcow2CachedTable, num_tables);
- c->table_array = qemu_try_blockalign(bs->file,
+ c->table_array = qemu_try_blockalign(bs->file->bs,
(size_t) num_tables * s->cluster_size);
if (!c->entries || !c->table_array) {
@@ -113,7 +171,7 @@ static int qcow2_cache_flush_dependency(BlockDriverState *bs, Qcow2Cache *c)
static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int ret = 0;
if (!c->entries[i].dirty || !c->entries[i].offset) {
@@ -126,7 +184,7 @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
if (c->depends) {
ret = qcow2_cache_flush_dependency(bs, c);
} else if (c->depends_on_flush) {
- ret = bdrv_flush(bs->file);
+ ret = bdrv_flush(bs->file->bs);
if (ret >= 0) {
c->depends_on_flush = false;
}
@@ -157,7 +215,7 @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
}
- ret = bdrv_pwrite(bs->file, c->entries[i].offset,
+ ret = bdrv_pwrite(bs->file->bs, c->entries[i].offset,
qcow2_cache_get_table_addr(bs, c, i), s->cluster_size);
if (ret < 0) {
return ret;
@@ -170,7 +228,7 @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int result = 0;
int ret;
int i;
@@ -185,7 +243,7 @@ int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c)
}
if (result == 0) {
- ret = bdrv_flush(bs->file);
+ ret = bdrv_flush(bs->file->bs);
if (ret < 0) {
result = ret;
}
@@ -237,6 +295,8 @@ int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c)
c->entries[i].lru_counter = 0;
}
+ qcow2_cache_table_release(bs, c, 0, c->size);
+
c->lru_counter = 0;
return 0;
@@ -245,7 +305,7 @@ int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c)
static int qcow2_cache_do_get(BlockDriverState *bs, Qcow2Cache *c,
uint64_t offset, void **table, bool read_from_disk)
{
- BDRVQcowState *s = bs->opaque;
+ BDRVQcow2State *s = bs->opaque;
int i;
int ret;
int lookup_index;
@@ -295,7 +355,8 @@ static int qcow2_cache_do_get(BlockDriverState *bs, Qcow2Cache *c,
BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
}
- ret = bdrv_pread(bs->file, offset, qcow2_cache_get_table_addr(bs, c, i),
+ ret = bdrv_pread(bs->file->bs, offset,
+ qcow2_cache_get_table_addr(bs, c, i),
s->cluster_size);
if (ret < 0) {
return ret;