On Tue, Jul 08, 2014 at 06:29:46PM +0200, Jon Severinsson wrote: > The new lzma2 compression options at the top of compress_blob_xz are > equivalent to using preset "0", exept for using a 1 MiB dictionary > (the same as preset "1"). This makes the memory usage at most 7.5 MiB > in the compressor, and 1 MiB in the decompressor, instead of the > previous 92 MiB in the compressor and 8 MiB in the decompressor. > > According to test-compress-benchmark this commit makes XZ compression > 20 times faster, with no increase in compressed data size. > Using more realistic test data (an ELF binary rather than repeating > ASCII letters 'a' through 'z' in order) it only provides a factor 10 > speedup, and at a cost if a 10% increase in compressed data size. > But that is still a worthwhile trade-off. > > According to test-compress-benchmark XZ compression is still 25 times > slower than LZ4, but the compressed data is one eighth the size. > Using more realistic test data XZ compression is only 18 times slower > than LZ4, and the compressed data is only one quarter the size. Nice improvement.
I made some whitespace modifications and added static to the options and pushed it. If you modified test-compress-benchmark to use more realistic data, please send a patch. Zbyszek _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
