diff options
| author | David Sterba <dsterba@suse.com> | 2016-11-02 13:27:45 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2016-11-09 13:47:31 +0100 |
| commit | 76fc07e3a6cdcb825859d833c83af16a34343f0b (patch) | |
| tree | 0f23444ed001cd33e54b246f78d3c46a4eca6b07 | |
| parent | 88edac358c1fbaaf28dccc9c0aa139577cdde6db (diff) | |
btrfs-progs: send: increase size of transfer buffer
4K is quite small, increase it to 64K. This reduces number of
context switches and calls to read. Kernel sends us about 50K of data
per read, so increasing the buffer further does not make any
improvement.
Example run on tests/cli-tests/004-send-parent-multi-subvol:
4K:
- ~800 context switches
- ~5000 calls to read
64K:
- ~450 context switches
- ~500 calls to read
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | cmds-send.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/cmds-send.c b/cmds-send.c index 6846b189..0608a106 100644 --- a/cmds-send.c +++ b/cmds-send.c @@ -44,6 +44,8 @@ #include "send.h" #include "send-utils.h" +#define SEND_BUFFER_SIZE (64 * 1024) + /* * Default is 1 for historical reasons, changing may break scripts that expect * the 'At subvol' message. @@ -222,7 +224,7 @@ static void *dump_thread(void *arg_) { int ret; struct btrfs_send *s = (struct btrfs_send*)arg_; - char buf[4096]; + char buf[SEND_BUFFER_SIZE]; int readed; while (1) { |