On Fri, 11 Sep 2009, René Scharfe wrote: > > Using zlib directly avoids the overhead of a pipe and of buffering the > output for blocked writes; surprisingly (to me), it isn't any faster. In fact, it should be slower. On SMP, you're quite likely better off using the pipe, and compressing on another CPU. Of course, it's usually the case that the compression is _so_ much slower than generating the tar-file (especially for the hot-cache case) that it doesn't matter or the pipe overhead is even a slowdown. But especially if generating the tar-file has some delays in it (cold-cache object lookup, whatever), the "compress in separate process" is likely simply better, because you can compress while the other process is looking up data for the tar. Linus -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html