From f77dcdbc76dbf9bade9739e85e1013639e535835 Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Fri, 20 Nov 2015 17:37:13 +0800 Subject: block-migration: limit the memory usage If we set migration speed in a very large value, block-migration will try to read all data to the memory. Because (block_mig_state.submitted + block_mig_state.read_done) * BLOCK_SIZE will be overflow, and it will be always less than rate limit. There is no need to read too many data into memory when the rate limit is very large. So limit the memory usage can fix the overflow problem. Signed-off-by: Wen Congyang Reviewed-by: Juan Quintela Reviewed-by: Stefan Hajnoczi Signed-off-by: Juan Quintela --- migration/block.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'migration/block.c') diff --git a/migration/block.c b/migration/block.c index 310e2b36dc..656f38f341 100644 --- a/migration/block.c +++ b/migration/block.c @@ -36,6 +36,8 @@ #define MAX_IS_ALLOCATED_SEARCH 65536 +#define MAX_INFLIGHT_IO 512 + //#define DEBUG_BLK_MIGRATION #ifdef DEBUG_BLK_MIGRATION @@ -665,7 +667,10 @@ static int block_save_iterate(QEMUFile *f, void *opaque) blk_mig_lock(); while ((block_mig_state.submitted + block_mig_state.read_done) * BLOCK_SIZE < - qemu_file_get_rate_limit(f)) { + qemu_file_get_rate_limit(f) && + (block_mig_state.submitted + + block_mig_state.read_done) < + MAX_INFLIGHT_IO) { blk_mig_unlock(); if (block_mig_state.bulk_completed == 0) { /* first finish the bulk phase */ -- cgit v1.2.1