Multifd sender thread performs zero page checking. If a page is
a zero page, only the page's metadata is sent to the receiver.
If a page is a normal page, the entire page's content is sent to
the receiver. This change adds a test hook to set the normal page
ratio. A zero page will be forced to be sent as a normal page. This
is useful for live migration performance analysis and optimization.
Signed-off-by: Hao Xiang
---
migration/options.c | 32
migration/options.h | 1 +
qapi/migration.json | 18 +++---
3 files changed, 48 insertions(+), 3 deletions(-)
diff --git a/migration/options.c b/migration/options.c
index b5f69031a9..aceb391338 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -79,6 +79,11 @@
#define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS5
#define DEFAULT_MIGRATE_ANNOUNCE_STEP100
+/*
+ * Parameter for multifd normal page test hook.
+ */
+#define DEFAULT_MIGRATE_MULTIFD_NORMAL_PAGE_RATIO 101
+
#define DEFINE_PROP_MIG_CAP(name, x) \
DEFINE_PROP_BOOL(name, MigrationState, capabilities[x], false)
@@ -181,6 +186,9 @@ Property migration_properties[] = {
MIG_MODE_NORMAL),
DEFINE_PROP_STRING("multifd-dsa-accel", MigrationState,
parameters.multifd_dsa_accel),
+DEFINE_PROP_UINT8("multifd-normal-page-ratio", MigrationState,
+ parameters.multifd_normal_page_ratio,
+ DEFAULT_MIGRATE_MULTIFD_NORMAL_PAGE_RATIO),
/* Migration capabilities */
DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@@ -862,6 +870,12 @@ int migrate_multifd_channels(void)
return s->parameters.multifd_channels;
}
+uint8_t migrate_multifd_normal_page_ratio(void)
+{
+MigrationState *s = migrate_get_current();
+return s->parameters.multifd_normal_page_ratio;
+}
+
MultiFDCompression migrate_multifd_compression(void)
{
MigrationState *s = migrate_get_current();
@@ -1261,6 +1275,14 @@ bool migrate_params_check(MigrationParameters *params,
Error **errp)
return false;
}
+if (params->has_multifd_normal_page_ratio &&
+params->multifd_normal_page_ratio > 100) {
+error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+ "multifd_normal_page_ratio",
+ "a value between 0 and 100");
+return false;
+}
+
return true;
}
@@ -1381,6 +1403,11 @@ static void
migrate_params_test_apply(MigrateSetParameters *params,
assert(params->multifd_dsa_accel->type == QTYPE_QSTRING);
dest->multifd_dsa_accel = params->multifd_dsa_accel->u.s;
}
+
+if (params->has_multifd_normal_page_ratio) {
+dest->has_multifd_normal_page_ratio = true;
+dest->multifd_normal_page_ratio = params->multifd_normal_page_ratio;
+}
}
static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1532,6 +1559,11 @@ static void migrate_params_apply(MigrateSetParameters
*params, Error **errp)
s->parameters.multifd_dsa_accel =
g_strdup(params->multifd_dsa_accel->u.s);
}
+
+if (params->has_multifd_normal_page_ratio) {
+s->parameters.multifd_normal_page_ratio =
+params->multifd_normal_page_ratio;
+}
}
void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
diff --git a/migration/options.h b/migration/options.h
index 56100961a9..21e3e7b0cf 100644
--- a/migration/options.h
+++ b/migration/options.h
@@ -95,6 +95,7 @@ const char *migrate_tls_creds(void);
const char *migrate_tls_hostname(void);
uint64_t migrate_xbzrle_cache_size(void);
const char *migrate_multifd_dsa_accel(void);
+uint8_t migrate_multifd_normal_page_ratio(void);
/* parameters setters */
diff --git a/qapi/migration.json b/qapi/migration.json
index 74465bc821..dedcdd076a 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -885,6 +885,9 @@
# characters. Setting this string to an empty string means disabling
# DSA accelerator offloading. Defaults to an empty string. (since 8.2)
#
+# @multifd-normal-page-ratio: Test hook setting the normal page ratio.
+# (Since 8.2)
+#
# Features:
#
# @deprecated: Member @block-incremental is deprecated. Use
@@ -918,7 +921,8 @@
'block-bitmap-mapping',
{ 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
'vcpu-dirty-limit',
- 'mode'] }
+ 'mode',
+ 'multifd-normal-page-ratio'] }
##
# @MigrateSetParameters:
@@ -1079,6 +1083,9 @@
# characters. Setting this string to an empty string means disabling
# DSA accelerator offloading. Defaults to an empty string. (since 8.2)
#
+# @multifd-normal-page-ratio: Test hook setting the normal page ratio.
+# (Since 8.2)
+#
# Features:
#
# @deprecated: Member @block-incremental is deprecated. Use
@@ -1133,7 +1140,8 @@
'features': [ 'unstable' ] },
