From: Hyman Huang(黄勇) <huang...@chinatelecom.cn>
Introduce migration dirty-limit capability, which can
be turned on before live migration and limit dirty
page rate durty live migration.
Introduce migrate_dirty_limit function to help check
if dirty-limit capability enabled during live migration.
Meanwhile, refactor vcpu_dirty_rate_stat_collect
so that period can be configured instead of hardcoded.
dirty-limit capability is kind of like auto-converge
but using dirty limit instead of traditional cpu-throttle
to throttle guest down. To enable this feature, turn on
the dirty-limit capability before live migration using
migratioin-set-capabilities, and set the parameters
"x-vcpu-dirty-limit-period", "vcpu-dirty-limit" suitably
to speed up convergence.
Signed-off-by: Hyman Huang(黄勇) <huang...@chinatelecom.cn>
---
migration/migration.c | 10 ++++++++++
migration/migration.h | 1 +
qapi/migration.json | 4 +++-
softmmu/dirtylimit.c | 11 ++++++++++-
4 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index a748fe5..d117bb4 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2508,6 +2508,15 @@ bool migrate_auto_converge(void)
return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
}
+bool migrate_dirty_limit(void)
+{
+ MigrationState *s;
+
+ s = migrate_get_current();
+
+ return s->enabled_capabilities[MIGRATION_CAPABILITY_DIRTY_LIMIT];
+}
+
bool migrate_zero_blocks(void)
{
MigrationState *s;
@@ -4437,6 +4446,7 @@ static Property migration_properties[] = {
DEFINE_PROP_MIG_CAP("x-zero-copy-send",
MIGRATION_CAPABILITY_ZERO_COPY_SEND),
#endif
+ DEFINE_PROP_MIG_CAP("x-dirty-limit", MIGRATION_CAPABILITY_DIRTY_LIMIT),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/migration/migration.h b/migration/migration.h
index cdad8ac..7fbb9f8 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -409,6 +409,7 @@ bool migrate_ignore_shared(void);
bool migrate_validate_uuid(void);
bool migrate_auto_converge(void);
+bool migrate_dirty_limit(void);
bool migrate_use_multifd(void);
bool migrate_pause_before_switchover(void);
int migrate_multifd_channels(void);
diff --git a/qapi/migration.json b/qapi/migration.json
index 8554d33..bc4bc96 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -477,6 +477,8 @@
# will be handled faster. This is a performance feature and
# should not affect the correctness of postcopy migration.
# (since 7.1)
+# @dirty-limit: Use dirty-limit to throttle down guest if enabled.
+# (since 7.1)
#
# Features:
# @unstable: Members @x-colo and @x-ignore-shared are experimental.
@@ -492,7 +494,7 @@
'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate',
{ 'name': 'x-ignore-shared', 'features': [ 'unstable' ] },
'validate-uuid', 'background-snapshot',
- 'zero-copy-send', 'postcopy-preempt'] }
+ 'zero-copy-send', 'postcopy-preempt', 'dirty-limit'] }
##
# @MigrationCapabilityStatus:
diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c
index 8d98cb7..1fdd8c6 100644
--- a/softmmu/dirtylimit.c
+++ b/softmmu/dirtylimit.c
@@ -23,6 +23,8 @@
#include "exec/memory.h"
#include "hw/boards.h"
#include "sysemu/kvm.h"
+#include "migration/misc.h"
+#include "migration/migration.h"
#include "trace.h"
/*
@@ -75,11 +77,18 @@ static bool dirtylimit_quit;
static void vcpu_dirty_rate_stat_collect(void)
{
+ MigrationState *s = migrate_get_current();
VcpuStat stat;
int i = 0;
+ int64_t period = DIRTYLIMIT_CALC_TIME_MS;
+
+ if (migrate_dirty_limit() &&
+ migration_is_active(s)) {
+ period = s->parameters.x_vcpu_dirty_limit_period;
+ }
/* calculate vcpu dirtyrate */
- vcpu_calculate_dirtyrate(DIRTYLIMIT_CALC_TIME_MS,
+ vcpu_calculate_dirtyrate(period,
&stat,
GLOBAL_DIRTY_LIMIT,
false);
--
1.8.3.1
