On Tue, Jul 01, 2014 at 12:32:10AM +0900, Sergey Senozhatsky wrote: > `struct workspace' used for zlib compression contains two zlib > z_stream-s: `def_strm' used in zlib_compress_pages(), and `inf_strm' > used in zlib_decompress/zlib_decompress_biovec(). None of these > functions use `inf_strm' and `def_strm' simultaniously, meaning that > for every compress/decompress operation we need only one z_stream > (out of two available). > > `inf_strm' and `def_strm' are different in size of ->workspace. For > inflate stream we vmalloc() zlib_inflate_workspacesize() bytes, for > deflate stream - zlib_deflate_workspacesize() bytes. On my system zlib > returns the following workspace sizes, correspondingly: 42312 and 268104 > (+ guard pages). > > Keep only one `z_stream' in `struct workspace' and use it for both > compression and decompression. Hence, instead of vmalloc() of two > z_stream->worskpace-s, allocate only one of size: > max(zlib_deflate_workspacesize(), zlib_inflate_workspacesize()) > > Signed-off-by: Sergey Senozhatsky <[email protected]>
Reviewed-by: David Sterba <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
