diff options
| author | Carl Hetherington <cth@carlh.net> | 2020-08-07 00:11:38 +0200 |
|---|---|---|
| committer | Carl Hetherington <cth@carlh.net> | 2020-08-07 00:17:04 +0200 |
| commit | 6c685e0cd6143dd7a8b1a9b5631b1bc9c0c4d687 (patch) | |
| tree | 9dc4bdf16691d20ff659d7b58cccddab2bd8c0d1 | |
| parent | 334d3cb564c72bd430a17c6e6f01aeb488fb191c (diff) | |
Use a much bigger block size when calling fwrite(). Each call to fwrite()
writes a few (often around 4) blocks of (I think) directory data to the
drive, so if you only fwrite() one block it ends up writing 1 block of
"payload" and 4 blocks of "admin". Using bigger blocks makes it faster;
an even bigger block than this makes it a little faster still, but not
significantly.
The extra block writing is seemingly triggered by fwrite() calling
ext4_block_cache_write_back(..., 0). A better fix is probably to call
this another way, at the end of the file copy.
| -rw-r--r-- | src/tools/dcpomatic_disk_writer.cc | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/tools/dcpomatic_disk_writer.cc b/src/tools/dcpomatic_disk_writer.cc index a2788e18b..45a5e8c60 100644 --- a/src/tools/dcpomatic_disk_writer.cc +++ b/src/tools/dcpomatic_disk_writer.cc @@ -89,7 +89,8 @@ using boost::optional; #ifdef DCPOMATIC_LINUX static PolkitAuthority* polkit_authority = 0; #endif -static uint64_t const block_size = 4096; +/* Use quite a big block size here, as ext4's fwrite() has quite a bit of overhead */ +static uint64_t const block_size = 4096 * 4096; static Nanomsg* nanomsg = 0; #define SHORT_TIMEOUT 100 @@ -128,7 +129,7 @@ write (boost::filesystem::path from, boost::filesystem::path to, uint64_t& total uint8_t* buffer = new uint8_t[block_size]; Digester digester; - int progress_frequency = 5000; + int progress_frequency = 1; int progress_count = 0; uint64_t remaining = file_size (from); while (remaining > 0) { |