On 2018/7/25 1:39 AM, Eric Biggers wrote: > On Wed, Jul 25, 2018 at 12:28:15AM +0800, Coly Li wrote: >> On 2018/7/24 12:44 PM, Eric Biggers wrote: >>> On Thu, Jul 19, 2018 at 12:55:45AM +0800, Coly Li wrote: >>>> This patch adds a kernel module to test the consistency of multiple crc >>>> calculation in Linux kernel. It is enabled with CONFIG_TEST_CRC enabled. >>>> >>>> The test results are printed into kernel message, which look like, >>>> >>>> test_crc: crc64_be: FAILED (0x03d4d0d85685d9a1, expected 0x3d4d0d85685d9a1f) >>>> >>>> kernel 0day system has framework to check kernel message, then the above >>>> result can be handled by 0day system. If crc calculation inconsistency >>>> happens, it can be detected quite soon. >>>> >>>> lib/test_crc.c is a testing frame work for many crc consistency >>>> testings. For now, there is only one test caes for crc64_be(). >>> >>> Are you aware there's already a CRC-32 test module: CONFIG_CRC32_SELFTEST and >>> lib/crc32test.c? Confusingly, your patch uses a different naming convention for >>> the new CRC-64 one, and puts the Kconfig option in a different place, and makes >>> it sound like it's a generic test for all CRC implementations rather than just >>> the CRC-64 one. Please use the existing convention (i.e. add >>> CONFIG_CRC64_SELFTEST and lib/crc64test.c) unless you have a strong argument for >>> why it should be done differently. >>> >>> (And I don't think it makes sense to combine all CRC tests into one module, >>> since you should be able to e.g. enable just CRC32 and CRC32_SELFTEST without >>> also pulling in a dependency on all the other CRC variants.) >>> >> >> Hi Eric, >> >> The purpose of test_crc is to provide a unified crc calculation >> consistency testing for 0day. So far it is only crc64, and I will add >> more test cases later. I see there is crc-32 test module, which does >> more testing then consistency check, and no unified format for 0day >> system to detect. This is why people suggested me to add this test >> framework. >> > > Actually the code in crc32test is nearly the same as what you're adding for > CRC-64. The CRC-32 test is longer because it's testing two different > polynomials "crc32" and "crc32c" as well as combining CRC's; neither of those is > relevant for CRC-64 yet, as you've implemented just one polynomial and there is > no function provided to combine CRC64's yet. The CRC-32 test also tests > performance, but if you don't believe CRC performance should be tested, then you > should remove the performance test from the existing module rather than > implementing a brand new test module just to remove the performance test... > > I still don't understand why you decided to do things differently for CRC-64, > when there were already CRC-32 tests that used a certain convention for the > Kconfig option, filename, etc. It's inconsistent and confusing. Again, please > use the existing convention unless you have a strong argument for why it should > be done differently. (And if you do want to do things differently, the existing > test should be converted first.) Hi Eric, So far only crc32 has selftesting code, it is hardly to be a convention IMHO. Anyway, considerate your comments and suggestion, I feel crc_test can be a separate patch from this series. Later I will post another series, which unify all crc test together into test_crc, including other crc calculations which don't have their testing code. Thanks. Coly Li -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
