From: Lidong Chen <lidongc...@tencent.com>
when migration with quick speed, mig_save_device_bulk invoke
bdrv_is_allocated too frequently, and cause vnc reponse slowly.
this patch limit the time used for bdrv_is_allocated.
Signed-off-by: Lidong Chen <lidongc...@tencent.com>
---
migration/block.c | 38 ++++++++++++++++++++++++++++++--------
1 file changed, 30 insertions(+), 8 deletions(-)
diff --git a/migration/block.c b/migration/block.c
index 7734ff7..9d7a8ee 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -39,6 +39,7 @@
#define MAX_IS_ALLOCATED_SEARCH 65536
#define MAX_INFLIGHT_IO 512
+#define BIG_DELAY 500000
//#define DEBUG_BLK_MIGRATION
@@ -110,6 +111,7 @@ typedef struct BlkMigState {
int transferred;
int prev_progress;
int bulk_completed;
+ int64_t time_ns_used;
/* Lock must be taken _inside_ the iothread lock and any AioContexts. */
QemuMutex lock;
@@ -272,16 +274,32 @@ static int mig_save_device_bulk(QEMUFile *f,
BlkMigDevState *bmds)
BlockBackend *bb = bmds->blk;
BlkMigBlock *blk;
int nr_sectors;
+ uint64_t ts1, ts2;
+ int ret = 0;
+ bool timeout_flag = false;
if (bmds->shared_base) {
qemu_mutex_lock_iothread();
aio_context_acquire(blk_get_aio_context(bb));
/* Skip unallocated sectors; intentionally treats failure as
* an allocated sector */
- while (cur_sector < total_sectors &&
- !bdrv_is_allocated(blk_bs(bb), cur_sector,
- MAX_IS_ALLOCATED_SEARCH, &nr_sectors)) {
- cur_sector += nr_sectors;
+ while (cur_sector < total_sectors) {
+ ts1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ ret = bdrv_is_allocated(blk_bs(bb), cur_sector,
+ MAX_IS_ALLOCATED_SEARCH, &nr_sectors);
+ ts2 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+
+ block_mig_state.time_ns_used += ts2 - ts1;
+
+ if (!ret) {
+ cur_sector += nr_sectors;
+ if (block_mig_state.time_ns_used > BIG_DELAY) {
+ timeout_flag = true;
+ break;
+ }
+ } else {
+ break;
+ }
}
aio_context_release(blk_get_aio_context(bb));
qemu_mutex_unlock_iothread();
@@ -292,6 +310,11 @@ static int mig_save_device_bulk(QEMUFile *f,
BlkMigDevState *bmds)
return 1;
}
+ if (timeout_flag) {
+ bmds->cur_sector = bmds->completed_sectors = cur_sector;
+ return 0;
+ }
+
bmds->completed_sectors = cur_sector;
cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
@@ -576,9 +599,6 @@ static int mig_save_device_dirty(QEMUFile *f,
BlkMigDevState *bmds,
}
bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, sector, nr_sectors);
- sector += nr_sectors;
- bmds->cur_dirty = sector;
-
break;
}
sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
@@ -756,6 +776,7 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
}
blk_mig_reset_dirty_cursor();
+ block_mig_state.time_ns_used = 0;
/* control the rate of transfer */
blk_mig_lock();
@@ -764,7 +785,8 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
qemu_file_get_rate_limit(f) &&
(block_mig_state.submitted +
block_mig_state.read_done) <
- MAX_INFLIGHT_IO) {
+ MAX_INFLIGHT_IO &&
+ block_mig_state.time_ns_used <= BIG_DELAY) {
blk_mig_unlock();
if (block_mig_state.bulk_completed == 0) {
/* first finish the bulk phase */
--
1.8.3.1
