Messages in this thread | | | Date | Mon, 13 Sep 2010 11:21:27 +0200 | From | Hannes Reinecke <> | Subject | Re: [PATCH 0/2] lio-target: Add support for libcrypto crc32c and crc32-intel offload |
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Nicholas A. Bellinger wrote: > From: Nicholas Bellinger <nab@linux-iscsi.org> > > Greetings all, > > This patch series converts the LIO-Target fabric module from using a legacy > internal slicing by 1x CRC32C algorithm to the slicing by 1x CRC32C available in > crc32c.ko, as well as initial support for the Nehalem series crc32c-intel.ko > instruction offload available since v2.6.27 in late 2008. > > So far this series has been lightly tested with a handful of Open-iSCSI client VMs > with the optimized crc32c-intel.ko offload case, and there appears to be some > HeaderDigest failures for one case with RHEL6 B2 x86_64, while Ubuntu i686 on > v2.6.27 and OpenSuse 11.2 x86_64 on v2.6.31 work as expected with HeaderDigest=CRC32C > and DataDigest=CRC32C using the offload on the LIO-Target side. > > Currently this patch disables the new iSCSI TPG attribute crc32c_x86_offload > to force the crc32c.ko slicing by x1 CRC32C algorithm until these compatibility > issues with existing libcrc32c clients can be properly resolved with the Nehalem > CRC32C offload instructions running on the LIO-Target side. > Due to a customer issue I had to revisit the CRC32 issue recently. And according to you the main reason for using your own CRC routines had been endianness issues. IE the in-kernel crc32c routines apparently weren't able to calculate the checksum in an endianness-independent manner. So a CRC calculated on a BE machine would fail to be validated by a LE machine and vice versa.
Has this been fixed / verified?
Cheers,
Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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