Add migrate_set_cache_size command

Change XBZRLE cache size in bytes (the size should be a power of 2, it will be
rounded down to the nearest power of 2).
If XBZRLE cache size is too small there will be many cache miss.

New query-migrate-cache-size QMP command and 'info migrate_cache_size' HMP
command to query cache value.

Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Orit Wasserman 2012-08-06 21:42:54 +03:00 committed by Juan Quintela
parent 17ad9b358b
commit 9e1ba4cc4e
9 changed files with 152 additions and 0 deletions

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@ -191,6 +191,16 @@ static struct {
.cache = NULL,
};
int64_t xbzrle_cache_resize(int64_t new_size)
{
if (XBZRLE.cache != NULL) {
return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
TARGET_PAGE_SIZE;
}
return pow2floor(new_size);
}
static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
int cont, int flag)
{

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@ -829,6 +829,26 @@ STEXI
@item migrate_cancel
@findex migrate_cancel
Cancel the current VM migration.
ETEXI
{
.name = "migrate_set_cache_size",
.args_type = "value:o",
.params = "value",
.help = "set cache size (in bytes) for XBZRLE migrations,"
"the cache size will be rounded down to the nearest "
"power of 2.\n"
"The cache size affects 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_cache_size,
},
STEXI
@item migrate_set_cache_size @var{value}
@findex migrate_set_cache_size
Set cache size to @var{value} (in bytes) for xbzrle migrations.
ETEXI
{
@ -1433,6 +1453,8 @@ show user network stack connection states
show migration status
@item info migrate_capabilities
show current migration capabilities
@item info migrate_cache_size
show current migration XBZRLE cache size
@item info balloon
show balloon information
@item info qtree

19
hmp.c
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@ -194,6 +194,12 @@ void hmp_info_migrate_capabilities(Monitor *mon)
qapi_free_MigrationCapabilityStatusList(caps);
}
void hmp_info_migrate_cache_size(Monitor *mon)
{
monitor_printf(mon, "xbzrel cache size: %" PRId64 " kbytes\n",
qmp_query_migrate_cache_size(NULL) >> 10);
}
void hmp_info_cpus(Monitor *mon)
{
CpuInfoList *cpu_list, *cpu;
@ -764,6 +770,19 @@ void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict)
qmp_migrate_set_downtime(value, NULL);
}
void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict)
{
int64_t value = qdict_get_int(qdict, "value");
Error *err = NULL;
qmp_migrate_set_cache_size(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");

2
hmp.h
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@ -26,6 +26,7 @@ void hmp_info_chardev(Monitor *mon);
void hmp_info_mice(Monitor *mon);
void hmp_info_migrate(Monitor *mon);
void hmp_info_migrate_capabilities(Monitor *mon);
void hmp_info_migrate_cache_size(Monitor *mon);
void hmp_info_cpus(Monitor *mon);
void hmp_info_block(Monitor *mon);
void hmp_info_blockstats(Monitor *mon);
@ -53,6 +54,7 @@ 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_capability(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_cache_size(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);

View File

@ -511,6 +511,25 @@ void qmp_migrate_cancel(Error **errp)
migrate_fd_cancel(migrate_get_current());
}
void qmp_migrate_set_cache_size(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;
}
s->xbzrle_cache_size = xbzrle_cache_resize(value);
}
int64_t qmp_query_migrate_cache_size(Error **errp)
{
return migrate_xbzrle_cache_size();
}
void qmp_migrate_set_speed(int64_t value, Error **errp)
{
MigrationState *s;

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@ -108,4 +108,6 @@ 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);
int64_t xbzrle_cache_resize(int64_t new_size);
#endif

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@ -2661,6 +2661,13 @@ static mon_cmd_t info_cmds[] = {
.help = "show current migration capabilities",
.mhandler.info = hmp_info_migrate_capabilities,
},
{
.name = "migrate_cache_size",
.args_type = "",
.params = "",
.help = "show current migration xbzrle cache size",
.mhandler.info = hmp_info_migrate_cache_size,
},
{
.name = "balloon",
.args_type = "",

View File

@ -1394,6 +1394,33 @@
##
{ 'command': 'migrate_set_speed', 'data': {'value': 'int'} }
##
# @migrate-set-cache-size
#
# Set XBZRLE cache size
#
# @value: cache size in bytes
#
# The size will be rounded 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-cache-size', 'data': {'value': 'int'} }
##
# @query-migrate-cache-size
#
# query XBZRLE cache size
#
# Returns: XBZRLE cache size in bytes
#
# Since: 1.2
##
{ 'command': 'query-migrate-cache-size', 'returns': 'int' }
##
# @ObjectPropertyInfo:
#

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@ -519,6 +519,50 @@ Example:
-> { "execute": "migrate_cancel" }
<- { "return": {} }
EQMP
{
.name = "migrate-set-cache-size",
.args_type = "value:o",
.mhandler.cmd_new = qmp_marshal_input_migrate_set_cache_size,
},
SQMP
migrate-set-cache-size
---------------------
Set cache size to be used by XBZRLE migration, the cache size will be rounded
down to the nearest power of 2
Arguments:
- "value": cache size in bytes (json-int)
Example:
-> { "execute": "migrate-set-cache-size", "arguments": { "value": 536870912 } }
<- { "return": {} }
EQMP
{
.name = "query-migrate-cache-size",
.args_type = "",
.mhandler.cmd_new = qmp_marshal_input_query_migrate_cache_size,
},
SQMP
query-migrate-cache-size
---------------------
Show cache size to be used by XBZRLE migration
returns a json-object with the following information:
- "size" : json-int
Example:
-> { "execute": "query-migrate-cache-size" }
<- { "return": 67108864 }
EQMP
{