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 <benoit.hud...@sap.com>
Signed-off-by: Petter Svard <pett...@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shrib...@sap.com>
Signed-off-by: Orit Wasserman <owass...@redhat.com>
---
arch_init.c | 9 +++++++++
hmp-commands.hx | 18 ++++++++++++++++++
hmp.c | 13 +++++++++++++
hmp.h | 1 +
migration.c | 23 ++++++++++++++++++++++-
migration.h | 2 ++
qapi-schema.json | 16 ++++++++++++++++
qmp-commands.hx | 23 +++++++++++++++++++++++
8 files changed, 104 insertions(+), 1 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 68010a6..08fe040 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>
@@ -192,6 +193,14 @@ static struct {
.cache = NULL,
};
+
+void xbzrle_cache_resize(int64_t new_size)
+{
+ if (XBZRLE.cache != NULL) {
+ cache_resize(XBZRLE.cache, new_size/TARGET_PAGE_SIZE);
+ }
+}
+
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 b3051a8..2473741 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -829,6 +829,24 @@ 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 will be round down to the nearest power
of 2.\n"
+ "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
+@item migrate_set_cachesize @var{value}
+@findex migrate_set_cache
+Set cache size to @var{value} (in bytes) for xbzrle migrations.
ETEXI
{
diff --git a/hmp.c b/hmp.c
index 67d4122..38f9067 100644
--- a/hmp.c
+++ b/hmp.c
@@ -753,6 +753,19 @@ 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 09ba198..7c5117d 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 d9c0cf5..16d47c0 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 =
@@ -498,6 +499,26 @@ 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;
+ }
+
+ /* no change */
+ if (value == s->xbzrle_cache_size) {
+ return;
+ }
+
+ s->xbzrle_cache_size = value;
+ xbzrle_cache_resize(value);
+}
+
void qmp_migrate_set_speed(int64_t value, Error **errp)
{
MigrationState *s;
diff --git a/migration.h b/migration.h
index eb0b822..cc7b433 100644
--- a/migration.h
+++ b/migration.h
@@ -107,4 +107,6 @@ 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 829be0f..ca12542 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1379,6 +1379,22 @@
{ 'command': 'migrate_set_speed', 'data': {'value': 'int'} }
##
+# @migrate_set_cachesize
+#
+# Set XBZRLE cache size
+#
+# @value: cache size in bytes
+#
+# The size will be round down to the nearest power of 2.
+# The cache size can be modified before and during ongoing migration
+#
+# Returns: nothing on success
+#
+# Since: 1.2
+##
+{ 'command': 'migrate_set_cachesize', 'data': {'value': 'int'} }
+
+##
# @ObjectPropertyInfo:
#
# @name: the name of the property
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2af4822..7a10d4f 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -520,6 +520,29 @@ 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, the cache size will be round
down
+to the nearset power of 2
+
+Arguments:
+
+- "value": cache size in bytes (json-int)
+
+Example:
+
+-> { "execute": "migrate_set_cachesize", "arguments": { "value": 512M } }
+<- { "return": {} }
+
+EQMP
{
.name = "migrate_set_speed",
--
1.7.7.6
