$ uname -a Linux nas 4.17.0-1-amd64 #1 SMP Debian 4.17.8-1 (2018-07-20) x86_64 GNU/Linux
$ dmesg | grep Btrfs [ 8.168408] Btrfs loaded, crc32c=crc32c-intel $ lsmod | grep crc32 crc32_pclmul 16384 0 libcrc32c 16384 1 btrfs crc32c_generic 16384 0 crc32c_intel 24576 2 $ grep CRC /boot/config-4.17.0-1-amd64 # CONFIG_PCIE_ECRC is not set # CONFIG_W1_SLAVE_DS2433_CRC is not set CONFIG_CRYPTO_CRC32C=m CONFIG_CRYPTO_CRC32C_INTEL=m CONFIG_CRYPTO_CRC32=m CONFIG_CRYPTO_CRC32_PCLMUL=m CONFIG_CRYPTO_CRCT10DIF=y CONFIG_CRYPTO_CRCT10DIF_PCLMUL=m CONFIG_CRC_CCITT=m CONFIG_CRC16=m CONFIG_CRC_T10DIF=y CONFIG_CRC_ITU_T=m CONFIG_CRC32=y # CONFIG_CRC32_SELFTEST is not set CONFIG_CRC32_SLICEBY8=y # CONFIG_CRC32_SLICEBY4 is not set # CONFIG_CRC32_SARWATE is not set # CONFIG_CRC32_BIT is not set # CONFIG_CRC4 is not set CONFIG_CRC7=m CONFIG_LIBCRC32C=m CONFIG_CRC8=m On Mon, 23 Jul 2018 at 16:14, Holger Hoffstätte <hol...@applied-asynchrony.com> wrote: > > Hi, > > While backporting a bunch of fixes to my own 4.16.x tree > (4.17 had a few too many bugs for my taste) I also ended up merging: > > df91f56adce1f: libcrc32c: Add crc32c_impl function > 9678c54388b6a: btrfs: Remove custom crc32c init code > > ..which AFAIK went into 4.17 and seemed harmless enough; after fixing up > a trivial context conflict it builds, runs, all good..except that btrfs > (apprently?) no longer uses the preferred crc32c-intel module, but the > crc32c-generic one instead. > > In order to rule out any mistakes on my part I built 4.18.0-rc6 and it > seems to have the same problem: > > Jul 23 15:55:09 ragnarok kernel: raid6: sse2x1 gen() 11267 MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: sse2x1 xor() 8110 MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: sse2x2 gen() 13409 MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: sse2x2 xor() 9137 MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: sse2x4 gen() 15884 MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: sse2x4 xor() 10579 MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: using algorithm sse2x4 gen() 15884 > MB/s > Jul 23 15:55:09 ragnarok kernel: raid6: .... xor() 10579 MB/s, rmw enabled > Jul 23 15:55:09 ragnarok kernel: raid6: using ssse3x2 recovery algorithm > Jul 23 15:55:09 ragnarok kernel: xor: automatically using best checksumming > function avx > Jul 23 15:55:09 ragnarok kernel: Btrfs loaded, crc32c=crc32c-generic > > I understand that the new crc32c_impl() function changed from > crypto_tfm_alg_driver_name() to crypto_shash_driver_name() - could this > be the reason? The module is loaded just fine, but apprently not used: > > $lsmod | grep crc32 > crc32_pclmul 16384 0 > crc32c_intel 24576 0 > > In other words, is this supposed to happen or is my kernel config somehow > no longer right? It worked before and doesn't look too wrong: > > $grep CRC /etc/kernels/kernel-config-x86_64-4.18.0-rc6 > # CONFIG_PCIE_ECRC is not set > CONFIG_CRYPTO_CRC32C=y > CONFIG_CRYPTO_CRC32C_INTEL=m > CONFIG_CRYPTO_CRC32=m > CONFIG_CRYPTO_CRC32_PCLMUL=m > # CONFIG_CRYPTO_CRCT10DIF is not set > CONFIG_CRC_CCITT=m > CONFIG_CRC16=y > # CONFIG_CRC_T10DIF is not set > CONFIG_CRC_ITU_T=y > CONFIG_CRC32=y > # CONFIG_CRC32_SELFTEST is not set > CONFIG_CRC32_SLICEBY8=y > # CONFIG_CRC32_SLICEBY4 is not set > # CONFIG_CRC32_SARWATE is not set > # CONFIG_CRC32_BIT is not set > # CONFIG_CRC4 is not set > # CONFIG_CRC7 is not set > CONFIG_LIBCRC32C=y > # CONFIG_CRC8 is not set > > Ultimately btrfs (and everything else) works, but the process of how > the kernel selects a crc32c implementation seems rather mysterious to me. :/ > > Any insights welcome. If it's a regression I can gladly test fixes. > > cheers > Holger > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
