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[Qemu-devel] [PATCH v10 8/9] Add set_cachesize command
From: |
Orit Wasserman |
Subject: |
[Qemu-devel] [PATCH v10 8/9] Add set_cachesize command |
Date: |
Wed, 16 May 2012 14:59:41 +0300 |
Change XBZRLE cache size in bytes (the size should be a power of 2).
If XBZRLE cache size is too small there will be many cache miss.
Signed-off-by: Benoit Hudzia <address@hidden>
Signed-off-by: Petter Svard <address@hidden>
Signed-off-by: Aidan Shribman <address@hidden>
Signed-off-by: Orit Wasserman <address@hidden>
---
arch_init.c | 7 +++++++
hmp-commands.hx | 15 +++++++++++++++
hmp.c | 13 +++++++++++++
hmp.h | 1 +
migration.c | 32 +++++++++++++++++++++++++++++++-
migration.h | 2 ++
qapi-schema.json | 13 +++++++++++++
qemu-common.h | 5 +++++
qmp-commands.hx | 22 ++++++++++++++++++++++
9 files changed, 109 insertions(+), 1 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 7ebdb7a..851e45d 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -24,6 +24,7 @@
#include <stdint.h>
#include <stdarg.h>
#include <stdlib.h>
+#include <math.h>
#ifndef _WIN32
#include <sys/types.h>
#include <sys/mman.h>
@@ -153,6 +154,12 @@ static struct {
Cache *cache;
} XBZRLE = {0};
+
+void xbzrle_cache_resize(int64_t order)
+{
+ cache_resize(XBZRLE.cache, pow(2, order));
+}
+
static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
int cont, int flag)
{
diff --git a/hmp-commands.hx b/hmp-commands.hx
index e14e7be..abc9403 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -829,6 +829,21 @@ STEXI
@item migrate_cancel
@findex migrate_cancel
Cancel the current VM migration.
+
+ETEXI
+
+ {
+ .name = "migrate_set_cachesize",
+ .args_type = "value:o",
+ .params = "value",
+ .help = "set cache size (in bytes) for XBZRLE migrations. The
cache size effects the number of cache misses. In case of a high cache miss
ratio you need to increase the cache size",
+ .mhandler.cmd = hmp_migrate_set_cachesize,
+ },
+
+STEXI
address@hidden migrate_set_cachesize @var{value}
address@hidden migrate_set_cache
+Set cache size to @var{value} (in bytes) for xbzrle migrations.
ETEXI
{
diff --git a/hmp.c b/hmp.c
index e73132b..0e4d63a 100644
--- a/hmp.c
+++ b/hmp.c
@@ -751,6 +751,19 @@ void hmp_migrate_set_downtime(Monitor *mon, const QDict
*qdict)
qmp_migrate_set_downtime(value, NULL);
}
+void hmp_migrate_set_cachesize(Monitor *mon, const QDict *qdict)
+{
+ int64_t value = qdict_get_int(qdict, "value");
+ Error *err = NULL;
+
+ qmp_migrate_set_cachesize(value, &err);
+ if (err) {
+ monitor_printf(mon, "%s\n", error_get_pretty(err));
+ error_free(err);
+ return;
+ }
+}
+
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)
{
int64_t value = qdict_get_int(qdict, "value");
diff --git a/hmp.h b/hmp.h
index 5f9d842..9559559 100644
--- a/hmp.h
+++ b/hmp.h
@@ -53,6 +53,7 @@ void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_cachesize(Monitor *mon, const QDict *qdict);
void hmp_set_password(Monitor *mon, const QDict *qdict);
void hmp_expire_password(Monitor *mon, const QDict *qdict);
void hmp_eject(Monitor *mon, const QDict *qdict);
diff --git a/migration.c b/migration.c
index ba11adb..4fb3b8a 100644
--- a/migration.c
+++ b/migration.c
@@ -22,6 +22,7 @@
#include "qemu_socket.h"
#include "block-migration.h"
#include "qmp-commands.h"
+#include <math.h>
//#define DEBUG_MIGRATION
@@ -43,7 +44,7 @@ enum {
#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */
-/* Migration XBZRLE cache size */
+/* Migration XBZRLE default cache size */
#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
static NotifierList migration_state_notifiers =
@@ -501,6 +502,35 @@ void qmp_migrate_cancel(Error **errp)
migrate_fd_cancel(migrate_get_current());
}
+void qmp_migrate_set_cachesize(int64_t value, Error **errp)
+{
+ MigrationState *s = migrate_get_current();
+
+ /* Check for truncation */
+ if (value != (size_t)value) {
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
+ "exceeding address space");
+ return;
+ }
+
+ value = MIN(UINT64_MAX, value);
+
+ /* no change */
+ if (value == s->xbzrle_cache_size) {
+ return;
+ }
+
+ /* power of 2 */
+ if (value != 1 && !is_power_of_2(value)) {
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
+ "needs to be power of 2");
+ return;
+ }
+
+ s->xbzrle_cache_size = value;
+ xbzrle_cache_resize(log2(value));
+}
+
void qmp_migrate_set_speed(int64_t value, Error **errp)
{
MigrationState *s;
diff --git a/migration.h b/migration.h
index 175c729..6a5bc0e 100644
--- a/migration.h
+++ b/migration.h
@@ -106,4 +106,6 @@ int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t
*dst, int dlen);
int migrate_use_xbzrle(void);
int64_t migrate_xbzrle_cache_size(void);
+void xbzrle_cache_resize(int64_t new_size);
+
#endif
diff --git a/qapi-schema.json b/qapi-schema.json
index 2887c51..4d30552 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1357,6 +1357,19 @@
{ 'command': 'migrate_set_speed', 'data': {'value': 'int'} }
##
+# @migrate_set_cachesize
+#
+# Set XBZRLE cache size
+#
+# @value: cache size in bytes
+#
+# Returns: nothing on success
+#
+# Since: 1.1
+##
+{ 'command': 'migrate_set_cachesize', 'data': {'value': 'int'} }
+
+##
# @ObjectPropertyInfo:
#
# @name: the name of the property
diff --git a/qemu-common.h b/qemu-common.h
index 3d0f66f..da44c17 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -415,4 +415,9 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b,
uint32_t c)
int uleb128_encode_small(uint8_t *out, uint32_t n);
int uleb128_decode_small(const uint8_t *in, uint32_t *n);
+static inline bool is_power_of_2(int64_t value)
+{
+ return !(value & (value - 1));
+}
+
#endif
diff --git a/qmp-commands.hx b/qmp-commands.hx
index f276e08..3bdbaae 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -520,6 +520,28 @@ Example:
<- { "return": {} }
EQMP
+{
+ .name = "migrate_set_cachesize",
+ .args_type = "value:o",
+ .mhandler.cmd_new = qmp_marshal_input_migrate_set_cachesize,
+ },
+
+SQMP
+migrate_set_cachesize
+---------------------
+
+Set cache size to be used by XBZRLE migration
+
+Arguments:
+
+- "value": cache size in bytes (json-int)
+
+Example:
+
+-> { "execute": "migrate_set_cachesize", "arguments": { "value": 512 } }
+<- { "return": {} }
+
+EQMP
{
.name = "migrate_set_speed",
--
1.7.7.6
- Re: [Qemu-devel] [PATCH v10 1/9] From: Isaku Yamahata <address@hidden>, (continued)
[Qemu-devel] [PATCH v10 2/9] Add migration capabilites, Orit Wasserman, 2012/05/16
[Qemu-devel] [PATCH v10 3/9] Add XBZRLE documentation, Orit Wasserman, 2012/05/16
[Qemu-devel] [PATCH v10 5/9] Add uleb encoding/decoding functions, Orit Wasserman, 2012/05/16
[Qemu-devel] [PATCH v10 6/9] Add save_block_hdr function, Orit Wasserman, 2012/05/16
[Qemu-devel] [PATCH v10 4/9] Add cache handling functions, Orit Wasserman, 2012/05/16
[Qemu-devel] [PATCH v10 7/9] Add XBZRLE to ram_save_block and ram_save_live, Orit Wasserman, 2012/05/16
[Qemu-devel] [PATCH v10 8/9] Add set_cachesize command,
Orit Wasserman <=
- Re: [Qemu-devel] [PATCH v10 8/9] Add set_cachesize command, Eric Blake, 2012/05/16
- Re: [Qemu-devel] [PATCH v10 8/9] Add set_cachesize command, Orit Wasserman, 2012/05/16
- Re: [Qemu-devel] [PATCH v10 8/9] Add set_cachesize command, Eric Blake, 2012/05/16
- Re: [Qemu-devel] [PATCH v10 8/9] Add set_cachesize command, Avi Kivity, 2012/05/17
- Re: [Qemu-devel] [PATCH v10 8/9] Add set_cachesize command, Orit Wasserman, 2012/05/17
[Qemu-devel] [PATCH v10 9/9] Add XBZRLE statistics, Orit Wasserman, 2012/05/16