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.) - Eric
