Further commit will add a benchmark (scripts/simplebench/bench-backup.py), which will show that backup works better with async parallel requests (previous commit) and disabled copy_range. So, let's disable copy_range by default.
Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]> --- qapi/block-core.json | 2 +- blockdev.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/qapi/block-core.json b/qapi/block-core.json index 5a21c24c1d..58eb2bcb86 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1376,7 +1376,7 @@ # Optional parameters for backup. These parameters don't affect # functionality, but may significantly affect performance. # -# @use-copy-range: Use copy offloading. Default true. +# @use-copy-range: Use copy offloading. Default false. # # @max-workers: Maximum number of parallel requests for the sustained background # copying process. Doesn't influence copy-before-write operations. diff --git a/blockdev.c b/blockdev.c index 0ed390abe0..1ac64d8ee2 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2788,7 +2788,7 @@ static BlockJob *do_backup_common(BackupCommon *backup, { BlockJob *job = NULL; BdrvDirtyBitmap *bmap = NULL; - BackupPerf perf = { .use_copy_range = true, .max_workers = 64 }; + BackupPerf perf = { .max_workers = 64 }; int job_flags = JOB_DEFAULT; if (!backup->has_speed) { -- 2.21.3
