On 09/01/2015 08:46 AM, Jason J. Herne wrote:
Remove traditional auto-converge static 30ms throttling code and replace it
with a dynamic throttling algorithm.
Additionally, be more aggressive when deciding when to start throttling.
Previously we waited until four unproductive memory passes. Now we begin
throttling after only two unproductive memory passes. Four seemed quite
arbitrary and only waiting for two passes allows us to complete the migration
faster.
Signed-off-by: Jason J. Herne <address@hidden>
Reviewed-by: Matthew Rosato <address@hidden>
---
arch_init.c | 88 ++++++++++++++++++---------------------------------
migration/migration.c | 4 +++
2 files changed, 34 insertions(+), 58 deletions(-)
+static void mig_throttle_guest_down(void)
+{
+ MigrationState *s = migrate_get_current();
+ uint64_t pct_initial =
+ s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL];
+ uint64_t pct_icrement =
+ s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT];
+
+ /* We have not started throttling yet. Let's start it. */
+ if (!cpu_throttle_active()) {
+ cpu_throttle_set(pct_initial);
+ } else {
+ /* Throttling already on, just increase the rate */
+ cpu_throttle_set(cpu_throttle_get_percentage() + pct_icrement);
What happens if the addition results in a percentage larger than 99?