On Wed, 2014-05-28 at 18:15 -0400, George Spelvin wrote: > crypto: crc32c-pclmul - Shrink K_table to 32-bit words > > There's no need for the K_table to be made of 64-bit words. For some > reason, the original authors didn't fully reduce the values modulo the > CRC32C polynomial, and so had some 33-bit number in there. They > can all be reduced to 32 bits. > > Doing that cuts the table size in half. Since the code depends on both > pclmulq and crc32, SSE 4.1 is obviously present, so we can use pmovzxdq > to fetch it in the correct format. > > Two other related fixes: > * K_table is read-only, so belongs in .text, not .data, and > * There's no need for more than 8-byte alignment
George, Can you do a tcrypt speed measurement with and without your changes? Check to see if there's any slowdown. Please make sure you pin the frequency of your cpu when running the test. e.g. echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor Thanks. Tim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
