From 3863ef31dcf04f977a94402348fec06179db58e0 Mon Sep 17 00:00:00 2001 From: Bob Pearson Date: Fri, 23 Mar 2012 15:02:22 -0700 Subject: crc32: simplify unit test code Replace the unit test provided in crc32.c, which doesn't have a makefile and doesn't compile with current headers, with a simpler self test routine that also gives a measure of performance and runs at module init time. The self test option can be enabled through a configuration option CONFIG_CRC32_SELFTEST. The test stresses the pre and post loops and is thus not very realistic since actual uses will likely have addresses and lengths that are at least 4 byte aligned. However, the main loop is long enough so that the performance is dominated by that loop. The expected values for crc32_le and crc32_be were generated with the original version of crc32.c using CRC_BITS_LE = 8 and CRC_BITS_BE = 8. These values were then used to check all the values of the BITS parameters in both the original and new versions. The performance results show some variability from run to run in spite of attempts to both warm the cache and reduce the amount of OS noise by limiting interrutps during the test. To get comparable results and to analyse options wrt performance the best time reported over a small sample of runs has been taken. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson Signed-off-by: Darrick J. Wong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'lib/Kconfig') diff --git a/lib/Kconfig b/lib/Kconfig index 028aba9e72a..d5a86aa441a 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -70,6 +70,16 @@ config CRC32 kernel tree does. Such modules that use library CRC32 functions require M here. +config CRC32_SELFTEST + bool "CRC32 perform self test on init" + default n + depends on CRC32 + help + This option enables the CRC32 library functions to perform a + self test on initialization. The self test computes crc32_le + and crc32_be over byte strings with random alignment and length + and computes the total elapsed time and number of bytes processed. + config CRC7 tristate "CRC7 functions" help -- cgit v1.2.3