From: David Miller <davem@xxxxxxxxxxxxx> Date: Wed, 31 May 2017 12:49:16 -0400 (EDT) > From: Eric Sandeen <sandeen@xxxxxxxxxxx> > Date: Wed, 31 May 2017 11:31:10 -0500 > >> On 5/31/17 11:19 AM, Eric Sandeen wrote: >>> On 5/31/17 10:53 AM, David Miller wrote: >>>> From: Anatoly Pugachev <matorola@xxxxxxxxx> >>>> Date: Wed, 31 May 2017 14:56:52 +0300 >>>> >>>>> While debugging occasional crc32c checksum errors with xfs disk reads on >>>>> sparc64 (T5 [sun4v] 3.6 GHz CPU ldom, debian unstable/sid), Eric have found >>>>> that crc32c sometimes returns wrong checksum for data. Eric made a simple >>>>> test kernel module (included), which produce the following results on my >>>>> sparc64 machines: >>> >>> cc: linux-xfs, because this problem cropped up on xfs/sparc. >> >> FWIW, the testcase (module which does >> >> crc = crc32c(CRC_SEED, data, 512); >> >> 1 million times in a loop on the same data, and printk's if >> the result ever changes) does not fail on x86_64 or ARM >> (well, not after a gcc bug was fixed on ARM ...) > > Is the machine doing things that would cause crc32c() operations in > interrupts (SCTP protocol traffic) or on other cpus? > > That's the danger in comparing other machines, the context and what's > running on them is different. Ok, I can reproduce this bug on my systems. I'll see if I can figure out what is going on. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
