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authorHyman Huang <yong.huang@smartx.com>2024-10-17 14:42:54 +0800
committerPeter Xu <peterx@redhat.com>2024-10-31 15:48:18 -0400
commit52ac968ab28b2e1eee2e083f19f2a70fdece5a2e (patch)
tree9ccd48373aeb80ad9c269d5c41dac8f5459d2ff3 /include
parent6a39ba7cab67da05b91e215142ce5781e77e5d9f (diff)
downloadfocaccia-qemu-52ac968ab28b2e1eee2e083f19f2a70fdece5a2e.tar.gz
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migration: Support periodic RAMBlock dirty bitmap sync
When VM is configured with huge memory, the current throttle logic
doesn't look like to scale, because migration_trigger_throttle()
is only called for each iteration, so it won't be invoked for a long
time if one iteration can take a long time.

The periodic dirty sync aims to fix the above issue by synchronizing
the ramblock from remote dirty bitmap and, when necessary, triggering
the CPU throttle multiple times during a long iteration.

This is a trade-off between synchronization overhead and CPU throttle
impact.

Signed-off-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/f61f1b3653f2acf026901103e1c73d157d38b08f.1729146786.git.yong.huang@smartx.com
[peterx: make prev_cnt global, and reset for each migration]
Signed-off-by: Peter Xu <peterx@redhat.com>
Diffstat (limited to 'include')
-rw-r--r--include/sysemu/cpu-throttle.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/sysemu/cpu-throttle.h b/include/sysemu/cpu-throttle.h
index d65bdef6d0..420702b8d3 100644
--- a/include/sysemu/cpu-throttle.h
+++ b/include/sysemu/cpu-throttle.h
@@ -65,4 +65,18 @@ bool cpu_throttle_active(void);
  */
 int cpu_throttle_get_percentage(void);
 
+/**
+ * cpu_throttle_dirty_sync_timer_tick:
+ *
+ * Dirty sync timer hook.
+ */
+void cpu_throttle_dirty_sync_timer_tick(void *opaque);
+
+/**
+ * cpu_throttle_dirty_sync_timer:
+ *
+ * Start or stop the dirty sync timer.
+ */
+void cpu_throttle_dirty_sync_timer(bool enable);
+
 #endif /* SYSEMU_CPU_THROTTLE_H */