X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fcompress_parallel.c;h=90b81dd8357ce5e2c02da6f165789e71f8c3bc0c;hb=dd3f804966f577b104eda649f572e8e765edc7ef;hp=e624819be77bb432a6c685ece3e2e039537c56b7;hpb=4dd45340f9fe3a533e0f1a9d6b79f8118e45ca2a;p=wimlib

diff --git a/src/compress_parallel.c b/src/compress_parallel.c
index e624819b..90b81dd8 100644
--- a/src/compress_parallel.c
+++ b/src/compress_parallel.c
@@ -7,19 +7,18 @@
 /*
  * Copyright (C) 2013 Eric Biggers
  *
- * This file is part of wimlib, a library for working with WIM files.
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option) any
+ * later version.
  *
- * wimlib is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free Software
- * Foundation; either version 3 of the License, or (at your option) any later
- * version.
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * details.
  *
- * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * wimlib; if not, see http://www.gnu.org/licenses/.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this file; if not, see http://www.gnu.org/licenses/.
  */
 
 #ifdef HAVE_CONFIG_H
@@ -62,7 +61,7 @@ struct compressor_thread_data {
 	struct wimlib_compressor *compressor;
 };
 
-#define MAX_CHUNKS_PER_MSG 2
+#define MAX_CHUNKS_PER_MSG 16
 
 struct message {
 	u8 *uncompressed_chunks[MAX_CHUNKS_PER_MSG];
@@ -433,7 +432,13 @@ new_parallel_chunk_compressor(int out_ctype, u32 out_chunk_size,
 	desired_num_threads = num_threads;
 
 	if (out_chunk_size < ((u32)1 << 23)) {
-		chunks_per_msg = MAX_CHUNKS_PER_MSG;
+		/* Relatively small chunks.  Use 2 messages per thread, each
+		 * with at least 2 chunks.  Use more chunks per message if there
+		 * are lots of threads and/or the chunks are very small.  */
+		chunks_per_msg = 2;
+		chunks_per_msg += num_threads * (65536 / out_chunk_size) / 16;
+		chunks_per_msg = max(chunks_per_msg, 2);
+		chunks_per_msg = min(chunks_per_msg, MAX_CHUNKS_PER_MSG);
 		msgs_per_thread = 2;
 	} else {
 		/* Big chunks: Just have one buffer per thread --- more would