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https://github.com/zfsonlinux/zfs/commit/0c593296e98e3ac95f14704e4cee6cedb2134990 https://github.com/zfsonlinux/zfs/commit/0c593296e98e3ac95f1... + https://gith

• yjftsjthsd-h 8y ago
  > Linux 5.0 compat: Disable vector instructions on 5.0+ kernels Isn't that going to kill performance?
  • simcop2387 8y ago
    Probably not going to be very noticeable, most of the cost in calculating the checksums is in IO, but it will mean that there's a lower ceiling on total possible performance. That also assumes though that the cost for handling the vector instructions in-kernel isn't higher than doing it without them. I believe that was part of the reason that the kernel started removing this from within drivers and other parts to begin with, the cost of saving all the floating point registers and other state is actually surprisingly expensive. So it may be a complete wash in the end anyway. If the kernel is no longer having to worry about saving those registers it can mean that the userspace doesn't pay that extra cost and now your compute ability is better for it without seriously affecting any of the rest of the system.